Publication Abstract from PubMed
BACKGROUND: In Escherichia coli, the enzymes of the biotin biosynthesis pathway are encoded by the bio operon. One of these enzymes, ATP-dependent dethiobiotin synthetase, catalyzes the carboxylation of 7,8-diaminopelargonic acid leading to the formation of the ureido ring of biotin. The enzyme belongs to the class of ATP-dependent carboxylases and we present here the first crystal structure determined for this class of enzyme. RESULTS: We have determined the crystal structure of homodimeric dethiobiotin synthetase to 1.65 A resolution. The subunit consists of a seven-stranded parallel beta-sheet, surrounded by alpha-helices. The sheet contains the classical mononucleotide-binding motif with a fingerprint peptide Gly-X-X-X-X-X-Gly-Lys-Thr. The mononucleotide binding part of the structure is very similar to the GTP-binding protein H-ras-p21 and thus all GTP-binding proteins. A comparison reveals that some of the residues, which in H-ras-p21 interact with the nucleotide and the metal ion, are conserved in the synthetase. CONCLUSIONS: The three-dimensional structure of dethiobiotin synthetase has revealed that ATP-dependent carboxylases contain the classical mononucleotide-binding fold. Considerable similarities to the structure of the GTP-binding protein H-ras-p21 were found, indicating that both proteins might have evolved from a common ancestral mononucleotide-binding fold.
Crystal structure of an ATP-dependent carboxylase, dethiobiotin synthetase, at 1.65 A resolution.,Huang W, Lindqvist Y, Schneider G, Gibson KJ, Flint D, Lorimer G Structure. 1994 May 15;2(5):407-14. PMID:8081756[1]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
