Extracellular secretion of noncatalytic plant cell wall-binding proteins by the cellulolytic thermophile Caldicellulosiruptor bescii.

ABSTRACT: Caldicellulosiruptor bescii efficiently degrades cellulose, xylan, and native grasses at high temperatures above 70°C under anaerobic conditions. C. bescii extracellularly secretes multidomain glycoside hydrolases along with proteins of unknown function. In this study, we analyzed the C. bescii proteins that bind to the cell walls of timothy grass by using mass spectrometry, and we identified four noncatalytic plant cell wall-binding proteins (PWBPs) with high pI values (9.2 to 9.6). A search of a conserved domain database showed that these proteins possess a common domain related to solute-binding proteins. In addition, 12 genes encoding PWBP-like proteins were detected in the C. bescii genomic sequence. To analyze the binding properties of PWBPs, recombinant PWBP57 and PWBP65, expressed

SUBMITTER: Yokoyama H 

PROVIDER: S-EPMC4248796 | biostudies-literature | 2014 Nov

REPOSITORIES: biostudies-literature