Activation of a [NiFe]-hydrogenase-4 isoenzyme by maturation proteases

Abstract

Maturation of [NiFe]-hydrogenases often involves specific proteases responsible for cleavage of the catalytic subunits. Escherichia coli HycI is the protease dedicated to maturation of the Hydrogenase-3 isoenzyme, a component of formate hydrogenlyase-1. In this work, it is demonstrated that a Pectobacterium atrosepticum HycI homologue, HyfK, is required for hydrogenase-4 activity, a component of formate hydrogenlyase-2, in that bacterium. The P. atrosepticum ΔhyfK mutant phenotype could be rescued by either P. atrosepticum hyfK or E. coli hycI on a plasmid. Conversely, an E. coli ΔhycI mutant was complemented by either E. coli hycI or P. atrosepticum hyfK in trans. E. coli is a rare example of a bacterium containing both hydrogenase-3 and hydrogenase-4, however the operon encoding hydrogenase-4 has no maturation protease gene. This work suggests HycI should be sufficient for maturation of both E. coli formate hydrogenlyases, however no formate hydrogenlyase-2 activity was detected in any E. coli strains tested here.

Proteomic analysis of Rhodospirillum rubrum after carbon monoxide exposure reveals an important effect on metallic cofactor biosynthesis

“…The proteins CooS is also significantly increased on 2D gels. As for CODH, the biosynthesis of [Ni-Fe]-hydrogenase active site is a multistep process involving at least six strictly conserved accessory proteins, namely HypABCDEF, in addition to a specific protease cleaving the C-terminal tail (HycI in E. coli, HyfK in Pectobacterium atrosepticum) [46][47][48]. In some bacteria such as Rubrivivax gelatinosus, hyp genes potentially responsible for CO-induced ECH maturation are clustered next and among the coo genes [49].…”

Microbial Musings – September 2020

“…In the paper in this issue from the group of Frank Sargent (@Prof_Sarge), with Tracy Palmer (@proftracypalmer) and Sarah Coulthurst (@SarahCoulthurs1), the authors continue to investigate the still elusive function of hydrogenase 4 (Hyd-4) in E. coli [4]. Despite many people trying to find evidence for the function of Hyd-4, which has been proposed to form a second FHL, FHL-2, no clear demonstration of function has been demonstrated.…”