Document Type
Article
Publication Date
9-2015
Publication Source
PLOS Pathogens
Abstract
A transcriptome analysis identified Vibrio vulnificus cabABC genes which were preferentially expressed in biofilms. The cabABC genes were transcribed as a single operon. The cabA gene was induced by elevated 3′,5′-cyclic diguanylic acid (c-di-GMP) and encoded a calcium-binding protein CabA. Comparison of the biofilms produced by the cabA mutant and its parent strain JN111 in microtiter plates using crystal-violet staining demonstrated that CabA contributed to biofilm formation in a calcium-dependent manner under elevated c-di-GMP conditions. Genetic and biochemical analyses revealed that CabA was secreted to the cell exterior through functional CabB and CabC, distributed throughout the biofilm matrix, and produced as the biofilm matured. These results, together with the observation that CabA also contributes to the development of rugose colony morphology, indicated that CabA is a matrix-associated protein required for maturation, rather than adhesion involved in the initial attachment, of biofilms. Microscopic comparison of the structure of biofilms produced by JN111 and the cabA mutant demonstrated that CabA is an extracellular matrix component essential for the development of the mature biofilm structures in flow cells and on oyster shells. Exogenously providing purified CabA restored the biofilm- and rugose colony-forming abilities of the cabA mutant when calcium was available. Circular dichroism and size exclusion analyses revealed that calcium binding induces CabA conformational changes which may lead to multimerization. Extracellular complementation experiments revealed that CabA can assemble a functional matrix only when exopolysaccharides coexist. Consequently, the combined results suggested that CabA is a structural protein of the extracellular matrix and multimerizes to a conformation functional in building robust biofilms, which may render V. vulnificus to survive in hostile environments and reach a concentrated infective dose.
Inclusive pages
1-32
ISBN/ISSN
1553-7366
Document Version
Published Version
Copyright
Copyright © 2015, Park et al.
Publisher
PLOS
Volume
11
Peer Reviewed
yes
Issue
9
eCommons Citation
Park, Jin Hwan; Jo, Youmi; Jang, Song Yee; Kwon, Haenaem; Irie, Yasuhiko; Parsek, Matthew R.; Kim, Myung Hee; and Choi, Sang Ho, "The cabABC Operon Essential for Biofilm and Rugose Colony Development in Vibrio vulnificus" (2015). Biology Faculty Publications. 213.
https://ecommons.udayton.edu/bio_fac_pub/213
Included in
Biology Commons, Biotechnology Commons, Cell Biology Commons, Genetics Commons, Microbiology Commons, Molecular Genetics Commons
Comments
This document is provided for download in compliance with the publisher's policy on self-archiving. Permission documentation is on file.
This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.