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The structure of aconitase
Author(s) -
Robbins A. H.,
Stout C. D.
Publication year - 1989
Publication title -
proteins: structure, function, and bioinformatics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.699
H-Index - 191
eISSN - 1097-0134
pISSN - 0887-3585
DOI - 10.1002/prot.340050406
Subject(s) - aconitase , side chain , cluster (spacecraft) , chemistry , active site , crystallography , stereochemistry , cysteine , domain (mathematical analysis) , molecule , crystal structure , protein structure , helix (gastropod) , enzyme , biochemistry , biology , mathematical analysis , ecology , mathematics , organic chemistry , snail , computer science , programming language , polymer
The crystal structure of the 80,000 Da FeS enzyme aconitase has been solved and refined at 2.1 Å resolution. The protein contains four domains; the first three from the N‐terminus are closely associated around the [3Fe–4S] cluster with all three cysteine ligands to the cluster being provided by the third domain. Associationof the larger C‐terminal domain with the first three domains createsan extensive cleft leading to the FeS cluster. Residues from all four domains contribute to the active site region, which is defined by the FeS cluster and a bound SO 4 2− ion. This region of the structure contains 4 Arg, 3 His, 3 Ser, 2 Asp, 1 Glu, 3 Asn, and 1 Gln residues, as well asseveral bound water molecules. Three of these side chains reside on a threeturn 3 10 helix in the first domain. The SO 4 2− ion is bound 9.3 Å from the center of the [3Fe–4S] cluster by the side chains of 2 Arg and 1 Gln rsidues. Each of 3 His side chains in the putative active site is paired with Asp or Glu side chains.