1nj8

Crystal Structure of Prolyl-tRNA Synthetase from Methanocaldococcus janaschii

spinqualitylabelsall models 1nj8, resolution 3.20Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 1nj8 is a 4 chain structure with sequence from Methanocaldococcus jannaschii. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Related: 1nj1, 1nj2, 1nj5, 1nj6 Gene: MJ1238 (Methanocaldococcus jannaschii) Activity: Proline--tRNA ligase, with EC number 6.1.1.15 Resources: FirstGlance, OCA, RCSB, PDBsum Function [SYP_METJA] Catalyzes the attachment of proline to tRNA(Pro) in a two-step reaction: proline is first activated by ATP to form Pro-AMP and then transferred to the acceptor end of tRNA(Pro). Can inadvertently accommodate and process non-cognate amino acids such as cysteine and alanine. 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 Cysteinyl-tRNA synthetase is an essential enzyme required for protein synthesis. Genes encoding this protein have not been identified in Methanocaldococcus jannaschii, Methanothermobacter thermautotrophicus, or Methanopyrus kandleri. It has previously been proposed that the prolyl-tRNA synthetase (ProRS) enzymes in these organisms recognize either proline or cysteine and can aminoacylate their cognate tRNAs through a dual-specificity mechanism. We report five crystal structures at resolutions between 2.6 and 3.2 A: apo M. jannaschii ProRS, and M. thermautotrophicus ProRS in apo form and in complex with cysteinyl-sulfamoyl-, prolyl-sulfamoyl-, and alanyl-sulfamoyl-adenylates. These aminoacyl-adenylate analogues bind to a single active-site pocket and induce an identical set of conformational changes in loops around the active site when compared with the ligand-free conformation of ProRS. The cysteinyl- and prolyl-adenylate analogues have similar, nanomolar affinities for M. thermautotrophicus ProRS. Homology modeling of tRNA onto these adenylate complexes places the 3'-OH of A76 in an appropriate position for the transfer of any of the three amino acids to tRNA. Thus, these structures explain recent biochemical experiments showing that M. jannaschii ProRS misacylates tRNA(Pro) with cysteine, and argue against the proposal that these archaeal ProRS enzymes possess the dual capacity to aminoacylate both tRNA(Pro) and tRNA(Cys) with their cognate amino acids. The structural basis of cysteine aminoacylation of tRNAPro by prolyl-tRNA synthetases.,Kamtekar S, Kennedy WD, Wang J, Stathopoulos C, Soll D, Steitz TA Proc Natl Acad Sci U S A. 2003 Feb 18;100(4):1673-8. Epub 2003 Feb 10. PMID:12578991 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Aminoacyl tRNA Synthetase

Proteopedia Page Contributors and Editors (what is this?)

OCA