3a3u | pdb_00003a3u

Crystal structure of MqnD (TTHA1568), a menaquinone biosynthetic enzyme from Thermus thermophilus HB8

spinqualitylabelsall models 3a3u, resolution 1.65Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 3a3u is a 1 chain structure with sequence from Thermus thermophilus HB8. This structure supersedes the now removed PDB entry 2dbp. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 1.65Å Ligands: 7PE, K, TLA Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function MQND_THET8 Catalyzes the conversion of cyclic dehypoxanthine futalosine (cyclic DHFL) into 1,4-dihydroxy-6-naphthoate, a step in the biosynthesis of menaquinone (MK, vitamin K2).[HAMAP-Rule:MF_00996] Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMed In many microorganisms, menaquinone is an essential lipid-soluble electron carrier. Recently, an alternative menaquinone biosynthetic pathway was found in some microorganisms [Hiratsuka, T., Furihata, K., Ishikawa, J., Yamashita, H., Itoh, N., Seto, H., Dairi, T., 2008. An alternative menaquinone biosynthetic pathway operating in microorganisms. Science 321, 1670-1673]. Here, we report the 1.55 A crystal structure of MqnD (TTHA1568) from Thermus thermophilus HB8, an enzyme within the alternative menaquinone biosynthetic pathway. The structure comprises two domains with alpha/beta structures, a large domain and a small domain. L(+)-Tartaric acid was bound to the pocket between the two domains, suggesting that this pocket is a putative active site. The conserved glycine residues at positions 78, 80 and 82 seem to act as hinges, allowing the substrate to access the pocket. Highly conserved residues, such as Asp14, Asp38, Asn43, Ser57, Thr107, Ile144, His145, Glu146, Leu176 and Tyr234, are located at this pocket, suggesting that these residues are involved in substrate binding and/or catalysis, and especially, His145 could function as a catalytic base. Since humans and their commensal intestinal bacteria, including lactobacilli, lack the alternative menaquinone biosynthetic pathway, this enzyme in pathogenic species, such as Helicobacter pylori and Campylobacter jejuni, is an attractive target for the development of chemotherapeutics. This high-resolution structure may contribute toward the development of its inhibitors. Crystal structure of MqnD (TTHA1568), a menaquinone biosynthetic enzyme from Thermus thermophilus HB8.,Arai R, Murayama K, Uchikubo-Kamo T, Nishimoto M, Toyama M, Kuramitsu S, Terada T, Shirouzu M, Yokoyama S J Struct Biol. 2009 Dec;168(3):575-81. Epub 2009 Jul 12. PMID:19602440 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

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