Maturation of the [Ni\u20134Fe\u20134S] active site of carbon monoxide dehydrogenases

Mériem Merrouch,Sébastien Dementin,Marco Lorenzi,Christophe Léger,Vincent Fourmond,Martino Benvenuti

doi:10.1007/s00775-018-1541-0

Abstract

Nickel-containing enzymes are diverse in terms of function and active site structure. In many cases, the biosynthesis of the active site depends on accessory proteins which transport and insert the Ni ion. We review and discuss the literature related to the maturation of carbon monoxide dehydrogenases (CODH) which bear a nickel-containing active site consisting of a [Ni–4Fe–4S] center called the C-cluster. The maturation of this center has been much less studied than that of other nickel-containing enzymes such as urease and NiFe hydrogenase. Several proteins present in certain CODH operons, including the nickel-binding proteins CooT and CooJ, still have unclear functions. We question the conception that the maturation of all CODH depends on the accessory protein CooC described as essential for nickel insertion into the active site. The available literature reveals biological variations in CODH active site biosynthesis.

Highlights

Nine nickel-containing enzymes have been discovered and characterized so far, but there exists certainly others [1, 2]
CooC acts as a chaperone that induces a conformational change of the active site of carbon monoxide dehydrogenases (CODH) by hydrolyzing ATP, and the folded active site of CODH spontaneously binds Ni [36]. We argued that the latter mechanism is more likely to be operational, since the Desulfovibrio vulgaris Hildenborough (Dv) CODH produced in the absence of its maturase CooC, contains hardly any nickel, is inactive and cannot be activated in vitro contrary to the enzyme that has been co-produced with CooC [5]
The structure of the active site of some of these enzymes is so elaborated that accessory proteins are necessary to bind the Ni ion and insert it

Summary

Introduction

Nine nickel-containing enzymes have been discovered and characterized so far, but there exists certainly others [1, 2]. The heterologous production of Ch CODH-I in E. coli, in the absence of CooC-1 leads to the formation of a an enzyme that contains three times less nickel, and is three times less active than when it is expressed in the presence of CooC [41].

Results

Conclusion