Nickel-chelatase activity of SirB variants mimicking the His arrangement in the naturally occurring nickel-chelatase CfbA.

ABSTRACT: Metal-tetrapyrrole cofactors are involved in multiple cellular functions, and chelatases are key enzymes for the biosynthesis of these cofactors. CfbA is an ancestral, homodimeric-type class II chelatase which is able to use not only Ni²⁺ as a physiological metal substrate, but also Co²⁺ as a nonphysiological substrate with higher activity than for Ni²⁺. The Ni/Co-chelatase function found in CfbA is also observed in SirB, a descendant, monomeric-type class II chelatase. This is despite the distinct active site structure of CfbA and SirB; specifically, CfbA shows a unique four His residue arrangement, unlike other monomeric class II chelatases such as SirB. Herein, we studied the Ni-chelatase activity of SirB variants R134H, L200H, and R134H/L200H, the latte

SUBMITTER: Oyamada Y 

PROVIDER: S-EPMC11301274 | biostudies-literature | 2024 Aug

REPOSITORIES: biostudies-literature