Kinetics and interaction studies between cytochrome c3 and Fe‐only hydrogenase from Desulfovibrio vulgaris hildenborough

Abstract

Hydrogenases from Desulfovibrio are found to catalyze hydrogen uptake with low potential multiheme cytochromes, such as cytochrome c3, acting as acceptors. The production of Fe-only hydrogenase from Desulfovibrio vulgaris Hildenborough was improved with respect to the growth phase and media to determine the best large-scale bacteria growth conditions. The interaction and electron transfer from Fe-only hydrogenase to multiheme cytochrome has been studied in detail by both BLAcore and steady-state measurements. The electron transfer between [Fe] hydrogenase and cytochrome c3 appears to be a cooperative phenomenon (h = 1.37). This behavior could be related to the conductivity properties of multihemic cytochromes. An apparent dissociation constant was determined (2 x 10(-7) M). The importance of the cooperativity for contrasting models proposed to describe the functional role of the hydrogenase/cytochrome c3 complex is discussed. Presently, the only determined structure is from [NiFe] hydrogenase and there are no obvious similarities between [NiFe] and [Fe] hydrogenase. Furthermore, no crystallographic data are available concerning [Fe] hydrogenase. The first results on crystallization and X-ray crystallography are reported.

Genome sequence of the dissimilatory metal ion–reducing bacterium Shewanella oneidensis

“…Hydrogenases are ubiquitous in prokaryotes and serve as intermediaries in numerous pathways involved in hydrogen production and/or consumption. Hydrogenases are classified into two metalloenzyme families based on the metal content of the active site: the Ni-containing hydrogenases (i.e., 19,20 .…”

A new sulfurtransferase from the hyperthermophilic bacterium Aquifex aeolicus

“…After centrifugation (30 min 3700 g, 4°C), the pellet was frozen and stored at )80°C. Periplasmic extraction was performed as described by Brugna et al [50]. Lactate dehydrogenase activity was measured to show whether the extract was contaminated by cytoplasmic proteins.…”

Family of Cytochromec7-Type Proteins fromGeobacter sulfurreducens: Structure of One Cytochromec7at 1.45 Å Resolution,

“…The hemes are numbered sequentially according to the cysteine residues to which they are attached in the amino acid sequence. Heme IV is suggested to interact with hydrogenases (13,14). While the level of sequence identity among the four-heme proteins is relatively low, ∼25%, the positions and orientations of the hemes in the three-dimensional structures are maintained (15).…”