PDBsum entry 3git

Transferase

PDB id: 3git

Contents

Protein chains

(+ 0 more) 422 a.a.

Ligands

SF4 ×6

H2S ×6

SO4 ×24

GOL ×6

Metals

_ZN ×6

Waters ×189

References listed in PDB file

Key reference

• Title: Novel domain arrangement in the crystal structure of a truncated acetyl-Coa synthase from moorella thermoacetica.
• Authors: A.Volbeda, C.Darnault, X.Tan, P.A.Lindahl, J.C.Fontecilla-Camps.
• Ref.: Biochemistry, 2009, 48, 7916-7926.
• PubMed id: 19650626

Abstract

Ni-dependent acetyl-CoA synthase (ACS) and CO dehydrogenase (CODH) constitute the central enzyme complex of the Wood-Ljungdahl pathway of acetyl-CoA formation. The crystal structure of a recombinant bacterial ACS lacking the N-terminal domain that interacts with CODH shows a large reorganization of the remaining two globular domains, producing a narrow cleft of suitable size, shape, and nature to bind CoA. Sequence comparisons with homologous archaeal enzymes that naturally lack the N-terminal domain show that many amino acids lining this cleft are conserved. Besides the typical [4Fe-4S] center, the A-cluster contains only one proximal metal ion that, according to anomalous scattering data, is most likely Cu or Zn. Incorporation of a functional Ni(2)Fe(4)S(4) A-cluster would require only minor structural rearrangements. Using available structures, a plausible model of the interaction between CODH and the smaller ACS in archaeal multienzyme complexes is presented, along with a discussion of evolutionary relationships of the archaeal and bacterial enzymes.