Related structures of neutral capsular polysaccharides of Acinetobacter baumannii isolates that carry related capsule gene clusters KL43, KL47, and KL88

2016 ◽  
Vol 435 ◽  
pp. 173-179 ◽  
Author(s):  
Alexander S. Shashkov ◽  
Johanna J. Kenyon ◽  
Nikolay P. Arbatsky ◽  
Mikhail M. Shneider ◽  
Anastasiya V. Popova ◽  
...  
Keyword(s):  
Acinetobacter Baumannii ◽  
Gene Clusters ◽  
Capsular Polysaccharides

scholarly journals Acinetobacter baumannii K106 and K112: Two Structurally and Genetically Related 6-Deoxy-l-talose-Containing Capsular Polysaccharides

2021 ◽  
Vol 22 (11) ◽  
pp. 5641
Author(s):  
Anastasiya A. Kasimova ◽  
Nikolay P. Arbatsky ◽  
Jacob Tickner ◽  
Johanna J. Kenyon ◽  
Ruth M. Hall ◽  
...  
Keyword(s):  
Acinetobacter Baumannii ◽  
Capsular Polysaccharide ◽  
Gene Clusters ◽  
13C Nmr Spectroscopy ◽  
Side Chain ◽  
Capsular Polysaccharides ◽  
Two Dimensional ◽  
Genome Sequences ◽  
1H And 13C Nmr ◽  
Biosynthesis Gene

Whole genome sequences of two Acinetobacter baumannii clinical isolates, 48-1789 and MAR24, revealed that they carry the KL106 and KL112 capsular polysaccharide (CPS) biosynthesis gene clusters, respectively, at the chromosomal K locus. The KL106 and KL112 gene clusters are related to the previously described KL11 and KL83 gene clusters, sharing genes for the synthesis of l-rhamnose (l-Rhap) and 6-deoxy-l-talose (l-6dTalp). CPS material isolated from 48-1789 and MAR24 was studied by sugar analysis and Smith degradation along with one- and two-dimensional 1H and 13C NMR spectroscopy. The structures of K106 and K112 oligosaccharide repeats (K units) l-6dTalp-(1→3)-D-GlcpNAc tetrasaccharide fragment share the responsible genes in the respective gene clusters. The K106 and K83 CPSs also have the same linkage between K units. The KL112 cluster includes an additional glycosyltransferase gene, Gtr183, and the K112 unit includes α l-Rhap side chain that is not found in the K106 structure. K112 further differs in the linkage between K units formed by the Wzy polymerase, and a different wzy gene is found in KL112. However, though both KL106 and KL112 share the atr8 acetyltransferase gene with KL83, only K83 is acetylated.

scholarly journals Structural comparison of Acinetobacter baumannii β-ketoacyl-acyl carrier protein reductases in fatty acid and aryl polyene biosynthesis

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Woo Cheol Lee ◽  
Sungjae Choi ◽  
Ahjin Jang ◽  
Kkabi Son ◽  
Yangmee Kim
Keyword(s):  
Fatty Acid ◽  
Acinetobacter Baumannii ◽  
Gene Cluster ◽  
Fatty Acid Synthase ◽  
Acyl Carrier Protein ◽  
Gene Clusters ◽  
Carrier Protein ◽  
Aryl Group ◽  
Visible Absorption

AbstractSome Gram-negative bacteria harbor lipids with aryl polyene (APE) moieties. Biosynthesis gene clusters (BGCs) for APE biosynthesis exhibit striking similarities with fatty acid synthase (FAS) genes. Despite their broad distribution among pathogenic and symbiotic bacteria, the detailed roles of the metabolic products of APE gene clusters are unclear. Here, we determined the crystal structures of the β-ketoacyl-acyl carrier protein (ACP) reductase ApeQ produced by an APE gene cluster from clinically isolated virulent Acinetobacter baumannii in two states (bound and unbound to NADPH). An in vitro visible absorption spectrum assay of the APE polyene moiety revealed that the β-ketoacyl-ACP reductase FabG from the A. baumannii FAS gene cluster cannot be substituted for ApeQ in APE biosynthesis. Comparison with the FabG structure exhibited distinct surface electrostatic potential profiles for ApeQ, suggesting a positively charged arginine patch as the cognate ACP-binding site. Binding modeling for the aryl group predicted that Leu185 (Phe183 in FabG) in ApeQ is responsible for 4-benzoyl moiety recognition. Isothermal titration and arginine patch mutagenesis experiments corroborated these results. These structure–function insights of a unique reductase in the APE BGC in comparison with FAS provide new directions for elucidating host–pathogen interaction mechanisms and novel antibiotics discovery.

Updated analysis of the surface carbohydrate gene clusters in the diverse panel of Acinetobacter baumannii isolates.

2021 ◽  
Author(s):  
Johanna J Kenyon ◽  
Ruth M. Hall
Keyword(s):  
Acinetobacter Baumannii ◽  
Capsular Polysaccharide ◽  
Gene Clusters ◽  
Outer Core ◽  
The Novel

To enhance the utility of the genetically diverse panel of Acinetobacter baumannii isolates reported recently by Galac and co-workers (AAC 64: e00840-20) and to identify the novel KL and OCL, all of the gene clusters that direct the biosynthesis of capsular polysaccharide and of the outer core of lipooligosaccharide, respectively, were re-examined. The nine KL and one OCL previously recorded as novel were identified and nine further novel KL and two OCL were found.

scholarly journals Involvement of a multifunctional rhamnosyltransferase in the synthesis of three related Acinetobacter baumannii capsular polysaccharides, K55, K74 and K85

2021 ◽  
Vol 166 ◽  
pp. 1230-1237
Author(s):  
Johanna J. Kenyon ◽  
Nikolay P. Arbatsky ◽  
Emma L. Sweeney ◽  
Yang Zhang ◽  
Sofya N. Senchenkova ◽  
...  
Keyword(s):  
Acinetobacter Baumannii ◽  
Capsular Polysaccharides

scholarly journals Acinetobacter baumannii K11 and K83 capsular polysaccharides have the same 6-deoxy- l -talose-containing pentasaccharide K units but different linkages between the K units

2017 ◽  
Vol 103 ◽  
pp. 648-655 ◽  
Author(s):  
Johanna J. Kenyon ◽  
Alexander S. Shashkov ◽  
Sof’ya N. Senchenkova ◽  
Mikhail M. Shneider ◽  
Bin Liu ◽  
...  
Keyword(s):  
Acinetobacter Baumannii ◽  
Capsular Polysaccharides

scholarly journals Acinetobacter baumanniiK27 and K44 capsular polysaccharides have the same K unit but different structures due to the presence of distinctwzygenes in otherwise closely related K gene clusters

Glycobiology ◽  
2015 ◽  
Vol 26 (5) ◽  
pp. 501-508 ◽  
Author(s):  
Alexander S Shashkov ◽  
Johanna J Kenyon ◽  
Sof'ya N Senchenkova ◽  
Mikhail M Shneider ◽  
Anastasiya V Popova ◽  
...  
Keyword(s):  
Gene Clusters ◽  
Capsular Polysaccharides

scholarly journals The K46 and K5 capsular polysaccharides produced by Acinetobacter baumannii NIPH 329 and SDF have related structures and the side-chain non-ulosonic acids are 4-O-acetylated by phage-encoded O-acetyltransferases

PLoS ONE ◽  
2019 ◽  
Vol 14 (6) ◽  
pp. e0218461 ◽  
Author(s):  
Johanna J. Kenyon ◽  
Nikolay P. Arbatsky ◽  
Mikhail M. Shneider ◽  
Anastasiya V. Popova ◽  
Andrei S. Dmitrenok ◽  
...  
Keyword(s):  
Acinetobacter Baumannii ◽  
Side Chain ◽  
Capsular Polysaccharides

Identification and structural determination of the capsular polysaccharides from two Acinetobacter baumannii clinical isolates, MG1 and SMAL

2011 ◽  
Vol 346 (7) ◽  
pp. 973-977 ◽  
Author(s):  
Eleonora Fregolino ◽  
Valentina Gargiulo ◽  
Rosa Lanzetta ◽  
Michelangelo Parrilli ◽  
Otto Holst ◽  
...  
Keyword(s):  
Acinetobacter Baumannii ◽  
Clinical Isolates ◽  
Capsular Polysaccharides ◽  
Structural Determination

scholarly journals Genetic Study of Capsular Switching between Neisseria meningitidis Sequence Type 7 Serogroup A and C Strains

2010 ◽  
Vol 78 (9) ◽  
pp. 3883-3888 ◽  
Author(s):  
Quan Wang ◽  
Zhujun Shao ◽  
Xiaoting Wang ◽  
Yuan Gao ◽  
Machao Li ◽  
...  
Keyword(s):  
Structural Analysis ◽  
Neisseria Meningitidis ◽  
Genetic Study ◽  
Gel Electrophoresis ◽  
Genetic Basis ◽  
Gene Clusters ◽  
Unique Sequence ◽  
Pulsed Field Gel Electrophoresis ◽  
Sequence Type ◽  
Capsular Polysaccharides

ABSTRACT Neisseria meningitidis is a leading cause of septicemia and meningitis worldwide. N. meningitidis capsular polysaccharides have been classified into 13 distinct serogroups which are defined by antibody reactivity and structural analysis, and the capsule plays an important role in virulence. Serogroups A, B, C, W135, and Y have been reported to be clinically important. Several newly identified serogroup C isolates belonging to the unique sequence type 7 (ST-7) were identified in China. Since most ST-7 isolates from China belonged to serogroup A, the newly identified ST-7 serogroup C strains were proposed to have arisen from those belonging to ST-7 serogroup A. In this study, six ST-7 serogroup C and three ST-7 serogroup A isolates were analyzed by pulsed-field gel electrophoresis to confirm their sequence type. In order to clarify the genetic basis of capsular switching between ST-7 serogroup A and C strains, the whole capsular gene clusters and surrounding genes of the two representative ST-7 strains belonging to serogroups A and C, respectively, were sequenced and compared. Potential recombination sites were analyzed using the RDP3 beta software, and recombination-related regions in two other ST-7 serogroup A and five ST-7 serogroup C strains were also sequenced and compared to the representative ST-7 serogroup A and C strain sequences.

scholarly journals Integrase-Controlled Excision of Metal-Resistance Genomic Islands in Acinetobacter baumannii

Genes ◽  
2018 ◽  
Vol 9 (7) ◽  
pp. 366 ◽  
Author(s):  
Zaaima AL-Jabri ◽  
Roxana Zamudio ◽  
Eva Horvath-Papp ◽  
Joseph Ralph ◽  
Zakariya AL-Muharrami ◽  
...  
Keyword(s):  
Heavy Metal ◽  
Acinetobacter Baumannii ◽  
Core Genome ◽  
Susceptibility Testing ◽  
Gene Clusters ◽  
Heavy Metal Resistance ◽  
Metal Resistance ◽  
Genomic Islands ◽  
Genome Plasticity ◽  
E Coli

Genomic islands (GIs) are discrete gene clusters encoding for a variety of functions including antibiotic and heavy metal resistance, some of which are tightly associated to lineages of the core genome phylogenetic tree. We have investigated the functions of two distinct integrase genes in the mobilization of two metal resistant GIs, G08 and G62, of Acinetobacter baumannii. Real-time PCR demonstrated integrase-dependent GI excision, utilizing isopropyl β-d-1-thiogalactopyranoside IPTG-inducible integrase genes in plasmid-based mini-GIs in Escherichia coli. In A. baumannii, integrase-dependent excision of the original chromosomal GIs could be observed after mitomycin C induction. In both E. coli plasmids and A. baumannii chromosome, the rate of excision and circularization was found to be dependent on the expression level of the integrases. Susceptibility testing in A. baumannii strain ATCC 17978, A424, and their respective ΔG62 and ΔG08 mutants confirmed the contribution of the GI-encoded efflux transporters to heavy metal decreased susceptibility. In summary, the data evidenced the functionality of two integrases in the excision and circularization of the two Acinetobacter heavy-metal resistance GIs, G08 and G62, in E. coli, as well as when chromosomally located in their natural host. These recombination events occur at different frequencies resulting in genome plasticity and may participate in the spread of resistance determinants in A. baumannii.

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