The crystal structure of DR2241 from Deinococcus radiodurans at 1.9 A resolution reveals a multi-domain protein with structural similarity to chelatases but also with two additional novel domains.
A unique family of proteins have been identified in the Deinococcus genus with an N-terminal cobalamin (vitamin B(12)) chelatase domain denoted CbiX and an additional unique C-terminal domain with unknown function. Here we report the first crystal structure from this new family of proteins with the structure of Deinococcus radiodurans protein DR2241. The structure reveals a multi-domain protein where domains A (residues 1-132) has the same fold as the small CbiX (CbiX(S)), domains A and B (residues 1-272) follow the chelatase super-family fold and the two additional unique domains C and D have no structural homologues. Domain D harbours the sequence motifs CxxC and CxxxC, in which DR2241 gives the first evidence that these motifs bind a [4Fe-4S] iron-sulphur cluster. In solution there are indications of multimeric forms, and in the crystallographic asymmetric unit a tetramer is found where domains C and D are involved in stabilising the tetrameric assembly.
Leiros
Hanna-Kirsti S
HK
Macromolecular Crystallography Group, European Synchrotron Radiation Facility (ESRF), BP 220, 6, Rue Jules Horowitz, F-38043 Grenoble Cedex 09, France.
McSweeney
Seán M
SM
D020816:Amino Acid Motifs; D001426:Bacterial Proteins / Q000737:chemistry; D018360:Crystallography, X-Ray; D034301:Deinococcus / Q000737:chemistry*; D019281:Dimerization; D007506:Iron-Sulfur Proteins / Q000737:chemistry; D017434:Protein Structure, Tertiary; D014805:Vitamin B 12
D001426:Bacterial Proteins; D007506:Iron-Sulfur Proteins; D014805:Vitamin B 12