Organization and sequence of four flagellin-encoding genes of Edwardsiella ictaluri |
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Authors: | Victor S Panangala Riccardo Russo Vicky L van Santen Karen G Wolfe & Phillip H Klesius |
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Institution: | United States Department of Agriculture, Agricultural Research Service, Aquatic Animal Health Research Unit, Auburn, AL, USA; Department of Pathobiology, College of Veterinary Medicine, Auburn University, Auburn, AL, USA; Department of Anatomy, Physiology and Pharmacology, College of Veterinary Medicine, Auburn University, Auburn, AL, USA |
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Abstract: | Edwardsiella ictaluri , the cause of enteric septicaemia in channel catfish ( Ictalurus punctatus ), is motile by means of peritrichous flagella. We determined the complete flagellin gene sequences and their organization in E. ictaluri by sequencing genomic segments from a λ-ZAP phage genomic library of E. ictaluri . Four flagellin genes ( fliC1, fliC2, fliC3 and fliC4 ) are arranged in tandem within 6 kb in the E. ictaluri genome. Each flagellin-coding sequence is preceded by a σ28 recognition site consensus sequence. The predicted amino acid sequences of all four flagellin proteins (between 36 and 37.5 kDa) are similar in the N-terminal (1–160 aa) and C-terminal (last 74 aa) portions and are divergent in the central portion of the proteins. Proteins encoded by flC1, fliC2 and fliC3 are more similar to each other (88–90% aa identity) than to the protein encoded by fliC4 (76–78% aa identity). basic local alignment search tool analysis of GenBank sequences showed that all flagellin aa sequences are more similar to those of Serratia marcescens (72–74% identity) than to those of Edwardsiella tarda (≤64% identity). Primary determination of E. ictaluri flagellin gene sequences facilitate advanced studies on the role of flagella in host–pathogen interaction. |
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Keywords: | flagellar proteins Edwardsiella ictaluri flagella σ28 promoter hook-associated protein FliD chaperone FliS |
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