Structural and Functional Studies of the Pseudomonas aeruginosa Minor Pilin, PilE

Many bacterial pathogens, including Pseudomonas aeruginosa, use type IVa pili (T4aP) for attachment and twitching motility. T4aP are composed primarily of major pilin subunits, which are repeatedly assembled and disassembled to mediate function. A group of pilin-like proteins, the minor pilins FimU...

Full description

Saved in:
Bibliographic Details
Published in:The Journal of biological chemistry 2015-10, Vol.290 (44), p.26856-26865
Main Authors: Nguyen, Ylan, Harvey, Hanjeong, Sugiman-Marangos, Seiji, Bell, Stephanie D., Buensuceso, Ryan N.C., Junop, Murray S., Burrows, Lori L.
Format: Article
Language:English
Subjects:
Amino Acid Sequence
bacterial adhesion
bacterial pathogenesis
bacterial two-hybrid
Binding Sites
Crystallography, X-Ray
Fimbriae Proteins - chemistry
Fimbriae Proteins - genetics
Fimbriae Proteins - metabolism
Fimbriae, Bacterial - chemistry
Gene Expression
Genes, Reporter
Genetic Complementation Test
Luminescent Proteins - genetics
Luminescent Proteins - metabolism
Microbiology
minor pilins
Models, Molecular
Molecular Sequence Data
Neisseria
Neisseria meningitidis
Neisseria meningitidis - chemistry
Neisseria meningitidis - genetics
Neisseria meningitidis - metabolism
PilC1
pilus assembly
PilY1
Protein Binding
Protein Folding
Protein Isoforms - chemistry
Protein Isoforms - genetics
Protein Isoforms - metabolism
Protein Multimerization
Protein Subunits - chemistry
Protein Subunits - genetics
Protein Subunits - metabolism
protein-protein interaction
Pseudomonas aeruginosa (P. aeruginosa)
Pseudomonas aeruginosa - chemistry
Pseudomonas aeruginosa - genetics
Pseudomonas aeruginosa - metabolism
Recombinant Fusion Proteins - chemistry
Recombinant Fusion Proteins - genetics
Recombinant Fusion Proteins - metabolism
Red Fluorescent Protein
Sequence Alignment
Structural Homology, Protein
twitching motility
type IV pili
X-ray crystallography
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Many bacterial pathogens, including Pseudomonas aeruginosa, use type IVa pili (T4aP) for attachment and twitching motility. T4aP are composed primarily of major pilin subunits, which are repeatedly assembled and disassembled to mediate function. A group of pilin-like proteins, the minor pilins FimU and PilVWXE, prime pilus assembly and are incorporated into the pilus. We showed previously that minor pilin PilE depends on the putative priming subcomplex PilVWX and the non-pilin protein PilY1 for incorporation into pili, and that with FimU, PilE may couple the priming subcomplex to the major pilin PilA, allowing for efficient pilus assembly. Here we provide further support for this model, showing interaction of PilE with other minor pilins and the major pilin. A 1.25 Å crystal structure of PilEΔ1–28 shows a typical type IV pilin fold, demonstrating how it may be incorporated into the pilus. Despite limited sequence identity, PilE is structurally similar to Neisseria meningitidis minor pilins PilXNm and PilVNm, recently suggested via characterization of mCherry fusions to modulate pilus assembly from within the periplasm. A P. aeruginosa PilE-mCherry fusion failed to complement twitching motility or piliation of a pilE mutant. However, in a retraction-deficient strain where surface piliation depends solely on PilE, the fusion construct restored some surface piliation. PilE-mCherry was present in sheared surface fractions, suggesting that it was incorporated into pili. Together, these data provide evidence that PilE, the sole P. aeruginosa equivalent of PilXNm and PilVNm, likely connects a priming subcomplex to the major pilin, promoting efficient assembly of T4aP. Background: Type IVa pilus (T4aP) assembly is primed by minor pilins. Results: Non-core subunit PilE interacts with core minor pilins and is incorporated into pili; PilE is structurally similar to Neisseria PilX and PilV. Conclusion: PilE connects the priming complex and the major pilin. Significance: This function may be broadly conserved for non-core minor components in T4aP.
ISSN:0021-9258
1083-351X
DOI:10.1074/jbc.M115.683334