当前位置： SCI文献检索 > PLoS Genetics期刊下所有文献 > Temporal and spatial regulation of protein cross-linking by the pre-assembled substrates of a Bacillus subtilis spore coat transglutaminase.

Temporal and spatial regulation of protein cross-linking by the pre-assembled substrates of a Bacillus subtilis spore coat transglutaminase.

Abstract：

:In many cases protein assemblies are stabilized by covalent bonds, one example of which is the formation of intra- or intermolecular ε-(γ-glutamyl)lysil cross-links catalyzed by transglutaminases (TGases). Because of the potential for unwanted cross-linking reactions, the activities of many TGases have been shown to be tightly controlled. Bacterial endospores are highly resilient cells in part because they are surrounded by a complex protein coat. Proteins in the coat that surrounds Bacillus subtilis endospores are crosslinked by a TGase (Tgl). Unlike other TGases, however, Tgl is produced in an active form, and efficiently catalyzes amine incorporation and protein cross-linking in vitro with no known additional requirements. The absence of regulatory factors raises questions as to how the activity of Tgl is controlled during spore coat assembly. Here, we show that substrates assembled onto the spore coat prior to Tgl production govern the localization of Tgl to the surface of the developing spore. We also show that Tgl residues important for substrate recognition are crucial for its localization. We identified the glutamyl (Q) and lysil (K) substrate docking sites and we show that residues on the Q side of Tgl are more important for the assembly of Tgl than those on the K side. Thus, the first step in the reaction cycle, the interaction with Q-substrates and formation of an acyl-enzyme intermediate, is also the determinant step in the localization of Tgl. Consistent with the idea that Tg exerts a "spotwelding" activity, cross-linking pre-formed assemblies, we show that C30 is an oblong hexamer in solution that is cross-linked in vitro into high molecular weight forms. Moreover, during the reaction, Tgl becomes part of the cross-linked products. We suggest that the dependency of Tgl on its substrates is used to accurately control the time, location and extent of the enzyme´s activity, directed at the covalent fortification of pre-assembled complexes at the surface of the developing spore.

journal_name

PLoS Genet

journal_title

PLoS genetics

authors

Fernandes CG,Martins D,Hernandez G,Sousa AL,Freitas C,Tranfield EM,Cordeiro TN,Serrano M,Moran CP Jr,Henriques AO

doi

10.1371/journal.pgen.1007912

subject

Has Abstract

pub_date

2019-04-08 00:00:00

pages

e1007912

issue

eissn

1553-7390

issn

1553-7404

pii

PGENETICS-D-18-01205

journal_volume

pub_type

杂志文章

在线工具

Temporal and spatial regulation of protein cross-linking by the pre-assembled substrates of a Bacillus subtilis spore coat transglutaminase.