scholarly journals Type IV pilus shapes a "bubble-jet" pattern opposing spatial intermixing of two interacting bacterial populations

2021 ◽  
Author(s):  
Miaoxiao Wang ◽  
Xiaoli Chen ◽  
Yinyin Ma ◽  
David Johnson ◽  
Yong Nie ◽  
...  
Keyword(s):  
Spatial Pattern ◽  
Spatial Patterns ◽  
Pseudomonas Stutzeri ◽  
Community Level ◽  
Type Iv Pilus ◽  
Bacterial Populations ◽  
Type Iv ◽  
Wide Range ◽  
Genes Encoding ◽  
Different Populations

Microbes are social organisms that commonly live in sessile biofilms. Spatial patterns of populations within biofilms can be an important determinant of community-level properties. The best-studied characteristics of spatial patterns is spatial intermixing of different populations. The specific levels of spatial intermixing critically contribute to how the dynamics and functioning of such communities are governed. However, the precise factors that determine spatial patterns and intermixing remain unclear. Here, we investigated the spatial patterning and intermixing of an engineered synthetic consortium composed of two Pseudomonas stutzeri strains that degrade salicylate via metabolic cross-feeding. We found that the consortium self-organizes across space to form a previously unreported spatial pattern (referred to here as a "bubble-jet" pattern) that exhibits a low level of intermixing. Interestingly, when the genes encoding for type IV pili were deleted from both strains, a highly intermixed spatial pattern developed and increased the productivity of the entire community. The intermixed pattern was maintained in a robust manner across a wide range of initial ratios between the two strains. Our findings show that the type IV pilus plays a role in mitigating spatial intermixing of different populations in surface-attached microbial communities, with consequences for governing community-level properties. These insights provide tangible clues for the engineering of synthetic microbial systems that perform highly in spatially structured environments.

scholarly journals Expression of Type IV Pili by Moraxella catarrhalis Is Essential for Natural Competence and Is Affected by Iron Limitation

2004 ◽  
Vol 72 (11) ◽  
pp. 6262-6270 ◽  
Author(s):  
Nicole R. Luke ◽  
Amy J. Howlett ◽  
Jianqiang Shao ◽  
Anthony A. Campagnari
Keyword(s):  
Moraxella Catarrhalis ◽  
Pathogenic Bacteria ◽  
Type Iv Pili ◽  
Protein Subunit ◽  
Electron Microscopic ◽  
Type Iv ◽  
Wide Range ◽  
Genes Encoding ◽  
Microscopic Studies

ABSTRACT Type IV pili, filamentous surface appendages primarily composed of a single protein subunit termed pilin, play a crucial role in the initiation of disease by a wide range of pathogenic bacteria. Although previous electron microscopic studies suggested that pili might be present on the surface of Moraxella catarrhalis isolates, detailed molecular and phenotypic analyses of these structures have not been reported to date. We identified and cloned the M. catarrhalis genes encoding PilA, the major pilin subunit, PilQ, the outer membrane secretin through which the pilus filament is extruded, and PilT, the NTPase that mediates pilin disassembly and retraction. To initiate investigation of the role of this surface organelle in pathogenesis, isogenic pilA, pilT, and pilQ mutants were constructed in M. catarrhalis strain 7169. Comparative analyses of the wild-type 7169 strain and three isogenic pil mutants demonstrated that M. catarrhalis expresses type IV pili that are essential for natural genetic transformation. Our studies suggest type IV pilus production by M. catarrhalis is constitutive and ubiquitous, although pilin expression was demonstrated to be iron responsive and Fur regulated. These data indicate that additional studies aimed at elucidating the prevalence and role of type IV pili in the pathogenesis and host response to M. catarrhalis infections are warranted.

scholarly journals The PilB-PilZ-FimX regulatory complex of the Type IV pilus from Xanthomonas citri

2021 ◽  
Vol 17 (8) ◽  
pp. e1009808
Author(s):  
Edgar E. Llontop ◽  
William Cenens ◽  
Denize C. Favaro ◽  
Germán G. Sgro ◽  
Roberto K. Salinas ◽  
...  
Keyword(s):  
Stable Complex ◽  
Type Iv Pilus ◽  
Xanthomonas Citri ◽  
Inner Membrane ◽  
Type Iv ◽  
Binary Complexes ◽  
Consistent Model ◽  
Wide Range ◽  
Regulatory Complex

Type IV pili (T4P) are thin and flexible filaments found on the surface of a wide range of Gram-negative bacteria that undergo cycles of extension and retraction and participate in a variety of important functions related to lifestyle, defense and pathogenesis. During pilus extensions, the PilB ATPase energizes the polymerization of pilin monomers from the inner membrane. In Xanthomonas citri, two cytosolic proteins, PilZ and the c-di-GMP receptor FimX, are involved in the regulation of T4P biogenesis through interactions with PilB. In vivo fluorescence microscopy studies show that PilB, PilZ and FimX all colocalize to the leading poles of X. citri cells during twitching motility and that this colocalization is dependent on the presence of all three proteins. We demonstrate that full-length PilB, PilZ and FimX can interact to form a stable complex as can PilB N-terminal, PilZ and FimX C-terminal fragments. We present the crystal structures of two binary complexes: i) that of the PilB N-terminal domain, encompassing sub-domains ND0 and ND1, bound to PilZ and ii) PilZ bound to the FimX EAL domain within a larger fragment containing both GGDEF and EAL domains. Evaluation of PilZ interactions with PilB and the FimX EAL domain in these and previously published structures, in conjunction with mutagenesis studies and functional assays, allow us to propose an internally consistent model for the PilB-PilZ-FimX complex and its interactions with the PilM-PilN complex in the context of the inner membrane platform of the X. citri Type IV pilus.

scholarly journals Genome Sequencing of Xanthomonas vasicola Pathovar vasculorum Reveals Variation in Plasmids and Genes Encoding Lipopolysaccharide Synthesis, Type-IV Pilus and Type-III Secretion Effectors

Pathogens ◽  
2014 ◽  
Vol 3 (1) ◽  
pp. 211-237 ◽  
Author(s):  
Arthur Wasukira ◽  
Max Coulter ◽  
Noorah Al-Sowayeh ◽  
Richard Thwaites ◽  
Konrad Paszkiewicz ◽  
...  
Keyword(s):  
Genome Sequencing ◽  
Type Iii Secretion ◽  
Type Iv Pilus ◽  
Type Iii ◽  
Type Iv ◽  
Genes Encoding

scholarly journals Requirement of Novel Competence Genes pilT andpilU of Pseudomonas stutzeri for Natural Transformation and Suppression of pilT Deficiency by a Hexahistidine Tag on the Type IV Pilus Protein PilAI

2001 ◽  
Vol 183 (16) ◽  
pp. 4694-4701 ◽  
Author(s):  
Stefan Graupner ◽  
Nicole Weger ◽  
Monika Sohni ◽  
Wilfried Wackernagel
Keyword(s):  
Amino Acid ◽  
Natural Transformation ◽  
Pseudomonas Stutzeri ◽  
Amino Acid Identity ◽  
Binding Motif ◽  
Dna Uptake ◽  
Twitching Motility ◽  
Type Iv Pilus ◽  
Type Iv ◽  
Insertional Inactivation

ABSTRACT The ubiquitous species Pseudomonas stutzeri has type IV pili, and these are essential for the natural transformation of the cells. An absolute transformation-deficient mutant obtained after transposon mutagenesis had an insertion in a gene which was termedpilT. The deduced amino acid sequence has identity with PilT of Pseudomonas aeruginosa (94%), Neisseria gonorrhoeae (67%), and other gram-negative species and it contains a nucleotide-binding motif. The mutant was hyperpiliated but defective for further pilus-associated properties, such as twitching motility and plating of pilus-specific phage PO4. [3H]thymidine-labeled DNA was bound by the mutant but not taken up. Downstream of pilT a gene, termedpilU, coding for a putative protein with 88% amino acid identity with PilU of P. aeruginosa was identified. Insertional inactivation did not affect piliation, twitching motility, or PO4 infection but reduced transformation to about 10%. The defect was fully complemented by PilU of nontransformable P. aeruginosa. When thepilAI gene (coding for the type IV pilus prepilin) was manipulated to code for a protein in which the six C-terminal amino acids were replaced by six histidine residues and then expressed from a plasmid, it gave a nonpiliated and twitching motility-defective phenotype in pilAI::Gmr cells but allowed transformability. Moreover, the mutant allele suppressed the absolute transformation deficiency caused by the pilT mutation. Considering the hypothesized role of pilT + in pilus retraction and the presumed requirement of retraction for DNA uptake, it is proposed that the pilT-independent transformation is promoted by PilA mutant protein either as single molecules or as minimal pilin assembly structures in the periplasm which may resemble depolymerized pili and that these cause the outer membrane pores to open for DNA entry.

scholarly journals Spatial Pattern Analysis of Sharka Disease (Plum pox virus Strain M) in Peach Orchards of Southern France

2003 ◽  
Vol 93 (12) ◽  
pp. 1543-1552 ◽  
Author(s):  
Sylvie Dallot ◽  
Tim Gottwald ◽  
Gérard Labonne ◽  
Jean-Bernard Quiot
Keyword(s):  
Spatial Pattern ◽  
Spatial Patterns ◽  
Disease Incidence ◽  
Point Pattern ◽  
Plum Pox Virus ◽  
Spatial Pattern Analysis ◽  
Individual Tree ◽  
Southern France ◽  
Wide Range ◽  
Sharka Disease

The spatial pattern of Sharka disease, caused by Plum pox virus (PPV) strain M, was investigated in 18 peach plots located in two areas of southern France. PPV infections were monitored visually for each individual tree during one to three consecutive years. Point pattern and correlation-type approaches were undertaken using the binary data directly or after parsing them in contiguous quadrats of 4, 9, and 16 trees. Ordinary runs generally revealed a low but variable proportion of rows with adjacent symptomatic trees. Aggregation of disease incidence was indicated by the θ parameter of the beta-binomial distribution and related indices in 15 of the 18 plots tested for at least one assessment date of each. When aggregation was detected, it was indicated at all quadrat sizes and tended to be a function of disease incidence, as shown by the binary form of Taylor's power law. Spatial analysis by distance indices (SADIE) showed a nonrandom arrangement of quadrats with infected trees in 14 plots. The detection of patch clusters enclosing quadrats with above-average density of symptomatic trees, ellipsoidal in shape and generally extending from 4 to 14 trees within rows and from 4 to 10 trees perpendicular to the rows, could be interpreted as local areas of influence of PPV spread. Spatial patterns at the plot scale were often characterized by the occurrence of several clusters of infected trees located up to 90 m apart in the direction of the rows. When several time assessments were available, increasing clustering over time was generally evidenced by stronger values of the clustering index and by increasing patch cluster size. The combination of the different approaches revealed a wide range of spatial patterns of PPV-M, from no aggregation to high aggregation of symptomatic trees at all spatial scales investigated. Such patterns suggested that aphid transmission to neighboring trees occurred frequently but was not systematic. The mechanism of primary virus introduction, the age and structure of the orchards when infected, and the diversity of vector species probably had a strong influence on the secondary spread of the disease. This study provides a more complete understanding of PPV-M patterns which could help to improve targeting of removal of PPV-infected trees for more effective disease control.

scholarly journals Type IV Pilus Genes pilA andpilC of Pseudomonas stutzeri Are Required for Natural Genetic Transformation, and pilA Can Be Replaced by Corresponding Genes from Nontransformable Species

2000 ◽  
Vol 182 (8) ◽  
pp. 2184-2190 ◽  
Author(s):  
Stefan Graupner ◽  
Verena Frey ◽  
Rozita Hashemi ◽  
Michael G. Lorenz ◽  
Gudrun Brandes ◽  
...  
Keyword(s):  
Amino Acid ◽  
Amino Acid Sequence ◽  
Amino Acid Sequence Identity ◽  
Pseudomonas Stutzeri ◽  
Type Iv Pili ◽  
Twitching Motility ◽  
Type Iv Pilus ◽  
Sequence Identity ◽  
Type Iv ◽  
Natural Genetic Transformation

ABSTRACT Pseudomonas stutzeri lives in terrestrial and aquatic habitats and is capable of natural genetic transformation. After transposon mutagenesis, transformation-deficient mutants were isolated from a P. stutzeri JM300 strain. In one of them a gene which coded for a protein with 75% amino acid sequence identity to PilC of Pseudomonas aeruginosa, an accessory protein for type IV pilus biogenesis, was inactivated. The presence of type IV pili was demonstrated by susceptibility to the type IV pilus-dependent phage PO4, by occurrence of twitching motility, and by electron microscopy. The pilC mutant had no pili and was defective in twitching motility. Further sequencing revealed that pilC is clustered in an operon with genes homologous to pilB andpilD of P. aeruginosa, which are also involved in pilus formation. Next to these genes but transcribed in the opposite orientation a pilA gene encoding a protein with high amino acid sequence identity to pilin, the structural component of type IV pili, was identified. Insertional inactivation of pilAabolished pilus formation, PO4 plating, twitching motility, and natural transformation. The amounts of 3H-labeled P. stutzeri DNA that were bound to competent parental cells and taken up were strongly reduced in the pilC andpilA mutants. Remarkably, the cloned pilA genes from nontransformable organisms like Dichelobacter nodosusand the PAK and PAO strains of P. aeruginosa fully restored pilus formation and transformability of the P. stutzeri pilA mutant (along with PO4 plating and twitching motility). It is concluded that the type IV pili of the soil bacterium P. stutzeri function in DNA uptake for transformation and that their role in this process is not confined to the species-specific pilin.

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