scholarly journals Type III Pilus of Corynebacteria: Pilus Length Is Determined by the Level of Its Major Pilin Subunit

2006 ◽  
Vol 188 (17) ◽  
pp. 6318-6325 ◽  
Author(s):  
Arlene Swierczynski ◽  
Hung Ton-That
Keyword(s):  
Gene Cluster ◽  
Biochemical Analysis ◽  
Gene Clusters ◽  
Inducible Promoter ◽  
The Other ◽  
Bacterial Genomes ◽  
Gram Positive ◽  
The Third ◽  
Pilin Subunit

ABSTRACT Multiple pilus gene clusters have been identified in several gram-positive bacterial genomes sequenced to date, including the Actinomycetales, clostridia, streptococci, and corynebacteria. The genome of Corynebacterium diphtheriae contains three pilus gene clusters, two of which have been previously characterized. Here, we report the characterization of the third pilus encoded by the spaHIG cluster. By using electron microscopy and biochemical analysis, we demonstrate that SpaH forms the pilus shaft, while SpaI decorates the structure and SpaG is largely located at the pilus tip. The assembly of the SpaHIG pilus requires a specific sortase located within the spaHIG pilus gene cluster. Deletion of genes specific for the synthesis and polymerization of the other two pilus types does not affect the SpaHIG pilus. Moreover, SpaH but not SpaI or SpaG is essential for the formation of the filament. When expressed under the control of an inducible promoter, the amount of the SpaH pilin regulates pilus length; no pili are assembled from an SpaH precursor that has an alanine in place of the conserved lysine of the SpaH pilin motif. Thus, the spaHIG pilus gene cluster encodes a pilus structure that is independently assembled and antigenically distinct from other pili of C. diphtheriae. We incorporate these findings in a model of sortase-mediated pilus assembly that may be applicable to many gram-positive pathogens.

scholarly journals Assembly of Distinct Pilus Structures on the Surface of Corynebacterium diphtheriae

2006 ◽  
Vol 188 (4) ◽  
pp. 1526-1533 ◽  
Author(s):  
Andrew H. Gaspar ◽  
Hung Ton-That
Keyword(s):  
Gene Cluster ◽  
Immunoelectron Microscopy ◽  
Gene Clusters ◽  
Corynebacterium Diphtheriae ◽  
Surface Structures ◽  
Specific Interactions ◽  
Bacterial Genomes ◽  
Gram Positive ◽  
Host Tissues

ABSTRACT Different surface organelles contribute to specific interactions of a pathogen with host tissues or infectious partners. Multiple pilus gene clusters potentially encoding different surface structures have been identified in several gram-positive bacterial genomes sequenced to date, including actinomycetales, clostridia, corynebacteria, and streptococci. Corynebacterium diphtheriae has been shown to assemble a pilus structure, with sortase SrtA essential for the assembly of a major subunit SpaA and two minor proteins, SpaB and SpaC. We report here the characterization of a second pilus consisting of SpaD, SpaE, and SpaF, of which SpaD and SpaE form the pilus shaft and SpaF may be located at the pilus tip. The structure of the SpaDEF pilus contains no SpaABC pilins as detected by immunoelectron microscopy. Neither deletion of spaA nor sortase srtA abolishes SpaDEF pilus formation. The assembly of the SpaDEF pilus requires specific sortases located within the SpaDEF pilus gene cluster. Although either sortase SrtB or SrtC is sufficient to polymerize SpaDF, the incorporation of SpaE into the SpaD pili requires sortase SrtB. In addition, an alanine in place of the lysine of the SpaD pilin motif abrogates pilus polymerization. Thus, SpaD, SpaE, and SpaF constitute a different pilus structure that is independently assembled and morphologically distinct from the SpaABC pili and possibly other pili of C. diphtheriae.

scholarly journals Morphological characterization of gram-positive and gram-negative bacteria from treated latex processing wastewater

2021 ◽  
Vol 1 (2) ◽  
pp. 32-36
Author(s):  
Farrah Aini Dahalan ◽  
Nor Azizah Parmin
Keyword(s):  
Oxygen Demand ◽  
Morphological Characterization ◽  
The Other ◽  
Morphological Properties ◽  
Morphological Observation ◽  
Gram Positive ◽  
Bacterial Colony ◽  
Gram Negative ◽  
Gram Staining

A preliminary morphological screening and isolation of bacterial colony from latex industrial wastewater was carried out. Bacteria colonies from latex processing wastewater were isolated from a local latex processing industry. It was found that 17 bacterial isolates had been purified grown on nutrient agar under 35˚C. The colonies were then purified and morphologically indicated via Gram staining and motility test. After morphological observation, it was identified that out of 17 isolates, 9 isolates were Gram positive and 8 isolates were Gram negative. There are 11 out of 17 colonies were rod-shaped bacterial colonies, while the other 6 colonies were cocci-shaped bacteria. There were 11 colonies of gliding bacteria, three colonies were non-motile bacteria and the other three colonies were flagellated bacteria. This study is only limited to morphological observation as the main aim of this study was to investigate the potential occurrence of viable growth in treated latex processing wastewater. The bacterial colonies were classified base on their morphological properties shown. This study has classified several genera such as Staphylococcus, Escherichia, Thiobacillus, Arthrobacter and other Genus. The growth curve of 17 isolates studied and the chemical oxygen demand were determined.

scholarly journals Discovery and characterization of a Gram-positive Pel polysaccharide biosynthetic gene cluster

2020 ◽  
Vol 16 (4) ◽  
pp. e1008281 ◽  
Author(s):  
Gregory B. Whitfield ◽  
Lindsey S. Marmont ◽  
Cedoljub Bundalovic-Torma ◽  
Erum Razvi ◽  
Elyse J. Roach ◽  
...  
Keyword(s):  
Gene Cluster ◽  
Biosynthetic Gene Cluster ◽  
Biosynthetic Gene ◽  
Gram Positive

scholarly journals Sortase-Catalyzed Assembly of Distinct Heteromeric Fimbriae in Actinomyces naeslundii

2007 ◽  
Vol 189 (8) ◽  
pp. 3156-3165 ◽  
Author(s):  
Arunima Mishra ◽  
Asis Das ◽  
John O. Cisar ◽  
Hung Ton-That
Keyword(s):  
Gene Cluster ◽  
Biochemical Analysis ◽  
Gene Clusters ◽  
Oral Diseases ◽  
Actinomyces Naeslundii ◽  
Molecular Investigation ◽  
A Minor ◽  
Assembly Pathways

ABSTRACT Two types of adhesive fimbriae are expressed by Actinomyces; however, the architecture and the mechanism of assembly of these structures remain poorly understood. In this study we characterized two fimbrial gene clusters present in the genome of Actinomyces naeslundii strain MG-1. By using immunoelectron microscopy and biochemical analysis, we showed that the fimQ-fimP-srtC1-fimR gene cluster encodes a fimbrial structure (designated type 1) that contains a major subunit, FimP, forming the shaft and a minor subunit, FimQ, located primarily at the tip. Similarly, the fimB-fimA-srtC2 gene cluster encodes a distinct fimbrial structure (designated type 2) composed of a shaft protein, FimA, and a tip protein, FimB. By using allelic exchange, we constructed an in-frame deletion mutant that lacks the SrtC2 sortase. This mutant produces abundant type 1 fimbriae and expresses the monomeric FimA and FimB proteins, but it does not assemble type 2 fimbriae. Thus, SrtC2 is a fimbria-specific sortase that is essential for assembly of the type 2 fimbriae. Together, our experiments pave the way for several lines of molecular investigation that are necessary to elucidate the fimbrial assembly pathways in Actinomyces and their function in the pathogenesis of different biofilm-related oral diseases.

scholarly journals CHARACTERIZATION OF LEUKIN: AN ANTIBACTERIAL FACTOR FROM LEUCOCYTES ACTIVE AGAINST GRAM-POSITIVE PATHOGENS

1956 ◽  
Vol 104 (6) ◽  
pp. 829-845 ◽  
Author(s):  
Robert C. Skarnes ◽  
Dennis W. Watson
Keyword(s):  
Amino Acids ◽  
The Other ◽  
Polymorphonuclear Leucocytes ◽  
Natural Immunity ◽  
Gram Positive ◽  
Gram Negative ◽  
Heat Stable ◽  
Apparent Similarity ◽  
Antibacterial Factor

A method has been described for the preparation of a potent antibacterial factor from rabbit polymorphonuclear leucocytes. Upon characterization, the factor was found to possess many properties in common with basic proteins. The amino acid analysis revealed that it contained a relatively large amount of arginine (17 per cent) and small amounts of the other two basic amino acids. It has therefore been identified as a protamine or protamine derivative. The leucocyte factor was very active against all Gram-positive pathogens tested but exhibited little or no action against Gram-negative species. A possible explanation of this phenomenon has been discussed. The factor was very heat-stable at acid and neutral pH and its staphylococcidal activity was blocked by glutamyl polypeptide, hyaluronic acid, and desoxyribonudeic acid. Because of the apparent similarity of the product studied here to other poorly defined leucocyte factors which had been termed leukins in the early literature, it is suggested that the name leukin be retained for it. The possible significance of this leukin in natural immunity has been discussed.

scholarly journals Genome mining of novel rubiginones from Streptomyces sp. CB02414 and characterization of the post-PKS modification steps in rubiginone biosynthesis

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Jingyan Zhang ◽  
Ying Sun ◽  
Yeji Wang ◽  
Xin Chen ◽  
Lu Xue ◽  
...  
Keyword(s):  
Gene Cluster ◽  
Biosynthetic Pathway ◽  
Scale Up ◽  
Genome Mining ◽  
Gene Clusters ◽  
Combinatorial Biosynthesis ◽  
Wild Type ◽  
Aromatic Polyketides ◽  
A Genome

Abstract Background Rubiginones belong to the angucycline family of aromatic polyketides, and they have been shown to potentiate the vincristine (VCR)-induced cytotoxicity against VCR-resistant cancer cell lines. However, the biosynthetic gene clusters (BGCs) and biosynthetic pathways for rubiginones have not been reported yet. Results In this study, based on bioinformatics analysis of the genome of Streptomyces sp. CB02414, we predicted the functions of the two type II polyketide synthases (PKSs) BGCs. The rub gene cluster was predicted to encode metabolites of the angucycline family. Scale-up fermentation of the CB02414 wild-type strain led to the discovery of eight rubiginones, including five new ones (rubiginones J, K, L, M, and N). Rubiginone J was proposed to be the final product of the rub gene cluster, which features extensive oxidation on the A-ring of the angucycline skeleton. Based on the production profiles of the CB02414 wild-type and the mutant strains, we proposed a biosynthetic pathway for the rubiginones in CB02414. Conclusions A genome mining strategy enabled the efficient discovery of new rubiginones from Streptomyces sp. CB02414. Based on the isolated biosynthetic intermediates, a plausible biosynthetic pathway for the rubiginones was proposed. Our research lays the foundation for further studies on the mechanism of the cytochrome P450-catalyzed oxidation of angucyclines and for the generation of novel angucyclines using combinatorial biosynthesis strategies.

Genetic Organization of the Escherichia coli K10 Capsule Gene Cluster: Identification and Characterization of Two Conserved Regions in Group III Capsule Gene Clusters Encoding Polysaccharide Transport Functions

1999 ◽  
Vol 181 (7) ◽  
pp. 2279-2285 ◽  
Author(s):  
Bradley R. Clarke ◽  
Rowan Pearce ◽  
Ian S. Roberts
Keyword(s):  
Escherichia Coli ◽  
Gene Cluster ◽  
Gene Clusters ◽  
Group Iii ◽  
Genetic Organization ◽  
Conserved Regions ◽  
Cluster Identification ◽  
Capsule Production ◽  
Identification And Characterization

ABSTRACT Analysis of the Escherichia coli K10 capsule gene cluster identified two regions, regions 1 and 3, conserved between different group III capsule gene clusters. Region 1 encodes homologues of KpsD, KpsM, KpsT, and KpsE proteins, and region 3 encodes homologues of the KpsC and KpsS proteins. An rfaH mutation abolished K10 capsule production, suggesting that expression of the K10 capsule was regulated by RfaH in a manner analogous to group II capsule gene clusters. An IS3 element and a φR73-like prophage, both of which may have played a role in the acquisition of group III capsule gene clusters, were detected flanking the K10 capsule genes.

scholarly journals Biochemical analysis of the methylic antigen of Paracoccidioides brasiliensis

1992 ◽  
Vol 34 (6) ◽  
pp. 511-516 ◽  
Author(s):  
Júnia Soares Hamdan ◽  
Maria Aparecida de Resende ◽  
Sarah Piancastelli Franzot ◽  
Eduardo Osório Cisalpino
Keyword(s):  
Total Lipid ◽  
Biochemical Composition ◽  
Biochemical Analysis ◽  
Paracoccidioides Brasiliensis ◽  
Synthetic Medium ◽  
The Other ◽  
Partial Characterization ◽  
Biochemical Characteristics ◽  
Carbohydrate Contents

Yeast forms of five strains of Paracoccidioides brasiliensis (SN, 2, 18, 192 and JT- 1) were cultured in a synthetic medium for obtaining methylic antigens. These antigens were lyophilized and studied for each strain, to determine their partial biochemical composition, through measurements of total lipid, protein and carbohydrate contents. Lipids of methylic antigens were purified and analysed for sterols, phospholipids, glycolipids, li-poproteins, and partial characterization of sterols. Significant differences were found among antigenic preparations derived from distinct P. brasiliensis strains, in relation to the quantitative determinations. On the other hand, sterol analysis revealed the presence of ergosterol, lanosterol and squalene in all samples. The diversity verified in the biochemical characteristics of antigens derived from different P. brasiliensis strains, confirm the need of using a pool of fungal samples in order to produce antigen preparations for serological procedures without hampering their sensitivity.

scholarly journals Discovery of Gene Cluster for Mycosporine-Like Amino Acid Biosynthesis from Actinomycetales Microorganisms and Production of a Novel Mycosporine-Like Amino Acid by Heterologous Expression

2014 ◽  
Vol 80 (16) ◽  
pp. 5028-5036 ◽  
Author(s):  
Kiyoko T. Miyamoto ◽  
Mamoru Komatsu ◽  
Haruo Ikeda
Keyword(s):  
Amino Acid ◽  
Gene Cluster ◽  
Gene Clusters ◽  
Biosynthetic Gene Cluster ◽  
Dependent Manner ◽  
Biosynthetic Gene ◽  
Biosynthetic Gene Clusters ◽  
Gram Positive ◽  
Content Type ◽  
Gram Positive Bacteria

ABSTRACTMycosporines and mycosporine-like amino acids (MAAs), including shinorine (mycosporine-glycine-serine) and porphyra-334 (mycosporine-glycine-threonine), are UV-absorbing compounds produced by cyanobacteria, fungi, and marine micro- and macroalgae. These MAAs have the ability to protect these organisms from damage by environmental UV radiation. Although no reports have described the production of MAAs and the corresponding genes involved in MAA biosynthesis from Gram-positive bacteria to date, genome mining of the Gram-positive bacterial database revealed that two microorganisms belonging to the orderActinomycetales,Actinosynnema mirumDSM 43827 andPseudonocardiasp. strain P1, possess a gene cluster homologous to the biosynthetic gene clusters identified from cyanobacteria. When the two strains were grown in liquid culture,Pseudonocardiasp. accumulated a very small amount of MAA-like compound in a medium-dependent manner, whereasA. mirumdid not produce MAAs under any culture conditions, indicating that the biosynthetic gene cluster ofA. mirumwas in a cryptic state in this microorganism. In order to characterize these biosynthetic gene clusters, each biosynthetic gene cluster was heterologously expressed in an engineered host,Streptomyces avermitilisSUKA22. Since the resultant transformants carrying the entire biosynthetic gene cluster controlled by an alternative promoter produced mainly shinorine, this is the first confirmation of a biosynthetic gene cluster for MAA from Gram-positive bacteria. Furthermore,S. avermitilisSUKA22 transformants carrying the biosynthetic gene cluster for MAA ofA. mirumaccumulated not only shinorine and porphyra-334 but also a novel MAA. Structure elucidation revealed that the novel MAA is mycosporine-glycine-alanine, which substitutesl-alanine for thel-serine of shinorine.

scholarly journals Biosynthesis of a Natural Polyketide-Isoprenoid Hybrid Compound, Furaquinocin A: Identification and Heterologous Expression of the Gene Cluster

2006 ◽  
Vol 188 (4) ◽  
pp. 1236-1244 ◽  
Author(s):  
Takashi Kawasaki ◽  
Yutaka Hayashi ◽  
Tomohisa Kuzuyama ◽  
Kazuo Furihata ◽  
Nobuya Itoh ◽  
...  
Keyword(s):  
Heterologous Expression ◽  
Gene Cluster ◽  
Mevalonate Pathway ◽  
Gene Clusters ◽  
Biosynthetic Gene Cluster ◽  
The Other ◽  
Upstream Region ◽  
Biosynthetic Gene ◽  
Hybrid Compound ◽  
Pathway Gene

ABSTRACT Furaquinocin (FQ) A, produced by Streptomyces sp. strain KO-3988, is a natural polyketide-isoprenoid hybrid compound that exhibits a potent antitumor activity. As a first step toward understanding the biosynthetic machinery of this unique and pharmaceutically useful compound, we have cloned an FQ A biosynthetic gene cluster by taking advantage of the fact that an isoprenoid biosynthetic gene cluster generally exists in flanking regions of the mevalonate (MV) pathway gene cluster in actinomycetes. Interestingly, Streptomyces sp. strain KO-3988 was the first example of a microorganism equipped with two distinct mevalonate pathway gene clusters. We were able to localize a 25-kb DNA region that harbored FQ A biosynthetic genes (fur genes) in both the upstream and downstream regions of one of the MV pathway gene clusters (MV2) by using heterologous expression in Streptomyces lividans TK23. This was the first example of a gene cluster responsible for the biosynthesis of a polyketide-isoprenoid hybrid compound. We have also confirmed that four genes responsible for viguiepinol [3-hydroxypimara-9(11),15-diene] biosynthesis exist in the upstream region of the other MV pathway gene cluster (MV1), which had previously been cloned from strain KO-3988. This was the first example of prokaryotic enzymes with these biosynthetic functions. By phylogenetic analysis, these two MV pathway clusters were identified as probably being independently distributed in strain KO-3988 (orthologs), rather than one cluster being generated by the duplication of the other cluster (paralogs).

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