1bkp

THERMOSTABLE THYMIDYLATE SYNTHASE A FROM BACILLUS SUBTILISTHERMOSTABLE THYMIDYLATE SYNTHASE A FROM BACILLUS SUBTILIS

Structural highlights 1bkp is a 2 chain structure with sequence from Bacillus subtilis. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 1.7Å Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function TYSY1_BACSU Catalyzes the reductive methylation of 2'-deoxyuridine-5'-monophosphate (dUMP) to 2'-deoxythymidine-5'-monophosphate (dTMP) while utilizing 5,10-methylenetetrahydrofolate (mTHF) as the methyl donor and reductant in the reaction, yielding dihydrofolate (DHF) as a by-product. This enzymatic reaction provides an intracellular de novo source of dTMP, an essential precursor for DNA biosynthesis.[HAMAP-Rule:MF_00008] 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 Unlike all other organisms studied to date, Bacillus subtilis expresses two different thymidylate synthases: bsTS-A and bsTS-B. bsTS-A displays enhanced enzymatic and structural thermal stability uncharacteristic of most TSs. Despite the high level of TS conservation across most species, bsTS-A shares low sequence identity (<40%) with the majority of TSs from other organisms. This TS and the TSs from Lactococcus lactis and phage Phi3T-to which it is most similar-have been of interest for some time since, by structure-based sequence alignment, they appear to lack several key residues shown by mutagenesis to be essential to enzymatic function [Greene, P. J., Yu, P. L., Zhao, J., Schiffer, C. A., and Santi, D. (1994) Protein Sci. 3, 1114-6]. In addition, bsTS-A demonstrates specific activity 2-3-fold higher than TS from Lactobacillus casei or Escherichia coli. We have solved the crystal structure of this unusual TS in four crystal forms to a maximum resolution of 1.7 A. Each of these crystal forms contains either one or two noncrystallographically related dimers. Stabilization of the beta-sheet dimer interface through a dramatic architecture of buttressed internal salt bridges maintains the structural integrity of bsTS-A at elevated temperatures. Melting curves of TSs from L. casei and E. coli are compared to that of TS-A from B. subtilis and correlated with numbers of hydrogen bonds, salt bridges, and the numbers of interactions localized to the dimer interface. Analysis of this structure will shed light on the conservation of function across diversity of sequence, as well as provide insights into the thermal stabilization of a highly conserved enzyme. Crystal structures of a unique thermal-stable thymidylate synthase from Bacillus subtilis.,Stout TJ, Schellenberger U, Santi DV, Stroud RM Biochemistry. 1998 Oct 20;37(42):14736-47. PMID:9778348 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Thymidylate synthase 3D structures

spinqualitylabelsall models 1bkp, resolution 1.70Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image