Sec-Dependent Secretion of Subtilase SptE in Haloarchaea Facilitates Its Proper Folding and Heterocatalytic Processing by Halolysin SptA Extracellularly

Abstract

While Tat-dependent haloarchaeal subtilases (halolysins) have been extensively studied, the information about Sec-dependent subtilases of haloarchaea is limited. Our results demonstrate that proper maturation of Sec-dependent subtilase SptE of Natrinema sp. strain J7-2 depends on the action of halolysin SptA from the same strain, yielding multiple hetero- and autocatalytic mature forms.

Dissecting the Arginine and Lysine Biosynthetic Pathways and Their Relationship in Haloarchaeon Natrinema gari J7-2 via Endogenous CRISPR-Cas System-Based Genome Editing

“…Nnm. gari J7-2 was isolated from a salt mine in China ( 36 ), and three extracellular subtilisin-like proteases (SptA, SptC, and SptE) of strain J7-2 have been characterized ( 37 – 40 ). Gene deletion analysis shows that the major extracellular protease SptA is not necessary for cell survival but facilitates the growth of strain J7-2 by degrading protein substrates into peptides and amino acids, which serve as nutrients for living cells ( 41 ).…”