| Literature DB >> 6346322 |
W C Stallings, T B Powers, K A Pattridge, J A Fee, M L Ludwig.
Abstract
The structure of iron superoxide dismutase (EC 1.15.1.1) from Escherichia coli has been determined at 3.1-A resolution. The dimeric molecule is constructed from identical subunits, which are two-domain polypeptides. The NH2-terminal domain is composed of two antiparallel crossing helices and the COOH-terminal domain is a three-layered structure characterized by mixed alpha/beta secondary structural features. The active center iron atoms, separated by 18 A and located near the monomer-monomer interface, are coordinated by two amino acid residues from each domain. Azide binding has been investigated by using difference Fourier techniques. Consistent with the notion of the independent evolution of the copper/zinc dismutase gene, the iron dismutase structure resembles the copper/zinc protein at neither the monomer nor the dimer level.Entities:
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Year: 1983 PMID: 6346322 PMCID: PMC394163 DOI: 10.1073/pnas.80.13.3884
Source DB: PubMed Journal: Proc Natl Acad Sci U S A ISSN: 0027-8424 Impact factor: 11.205