Novel Domain Arrangement in the Crystal Structure of a Truncated Acetyl-CoA Synthase from Moorella thermoacetica

作者：Volbeda Anne^*; Darnault Claudine; Tan Xiangshi; Lindahl Paul A; Fontecilla Camps Juan C

来源：Biochemistry, 2009, 48(33): 7916-7926.

DOI：10.1021/bi9003952

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.

• 出版日期2009-8-25
• 单位复旦大学; 中国地震局