Conformational determinants necessary for secretion of Paecilomyces thermophila β-1,4-xylosidase that lacks a signal peptide.

ABSTRACT: In this study, we investigated the secretion mechanism of the hyper-secretion signal peptide-lacking β-xylosidase PtXyl43, a non-classically secreted protein, from the fungus Paecilomyces thermophila in Escherichia coli BL21(DE3). PtXyl43 secretion is a two-step process, and the second step is accompanied by cell periplasmic leakage, indicating that PtXyl43 secretion is the result of semi-specific secretion. Homology modeling of PtXyl43 suggested that PtXyl43 had a canonical GH43 family β-xylosidase structure containing five blades. Seventeen blade deletions or circular mutants were designed to identify the conformational motif(s) involved in secretion. These mutants were expressed as recombinant, codon-optimized proteins in E. coli. Notably, only mutants containing blades 2-4 were effecti

SUBMITTER: Yang Y 

PROVIDER: S-EPMC5783984 | biostudies-literature | 2018 Jan

REPOSITORIES: biostudies-literature