1e6c: Difference between revisions
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==Overview== | ==Overview== | ||
Shikimate kinase, despite low sequence identity, has been shown to be, structurally a member of the nucleoside monophosphate (NMP) kinase family, which includes adenylate kinase. In this paper we have explored the roles, of residues in the P-loop of shikimate kinase, which forms the binding, site for nucleotides and is one of the most conserved structural features, in proteins. In common with many members of the P-loop family, shikimate, kinase contains a cysteine residue 2 amino acids upstream of the essential, lysine residue; the side chains of these residues are shown to form an ion, pair. The C13S mutant of shikimate kinase was found to be enzymatically, active, whereas the K15M mutant was inactive. However, the latter mutant, had both increased thermostability and affinity for ATP ... | Shikimate kinase, despite low sequence identity, has been shown to be, structurally a member of the nucleoside monophosphate (NMP) kinase family, which includes adenylate kinase. In this paper we have explored the roles, of residues in the P-loop of shikimate kinase, which forms the binding, site for nucleotides and is one of the most conserved structural features, in proteins. In common with many members of the P-loop family, shikimate, kinase contains a cysteine residue 2 amino acids upstream of the essential, lysine residue; the side chains of these residues are shown to form an ion, pair. The C13S mutant of shikimate kinase was found to be enzymatically, active, whereas the K15M mutant was inactive. However, the latter mutant, had both increased thermostability and affinity for ATP when compared to, the wild-type enzyme. The structure of the K15M mutant protein has been, determined at 1.8 A, and shows that the organization of the P-loop and, flanking regions is heavily disturbed. This indicates that, besides its, role in catalysis, the P-loop lysine also has an important structural, role. The structure of the K15M mutant also reveals that the formation of, an additional arginine/aspartate ion pair is the most likely reason for, its increased thermostability. From studies of ligand binding it appears, that, like adenylate kinase, shikimate kinase binds substrates randomly, and in a synergistic fashion, indicating that the two enzymes have similar, catalytic mechanisms. | ||
==About this Structure== | ==About this Structure== | ||
1E6C is a | 1E6C is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Erwinia_chrysanthemi Erwinia chrysanthemi] with PO4, CL, MRD and MPD as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Shikimate_kinase Shikimate kinase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.7.1.71 2.7.1.71] Structure known Active Sites: POA and POB. Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=1E6C OCA]. | ||
==Reference== | ==Reference== | ||
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[[Category: transferase]] | [[Category: transferase]] | ||
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Revision as of 15:03, 5 November 2007
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K15M MUTANT OF SHIKIMATE KINASE FROM ERWINIA CHRYSANTHEMI
OverviewOverview
Shikimate kinase, despite low sequence identity, has been shown to be, structurally a member of the nucleoside monophosphate (NMP) kinase family, which includes adenylate kinase. In this paper we have explored the roles, of residues in the P-loop of shikimate kinase, which forms the binding, site for nucleotides and is one of the most conserved structural features, in proteins. In common with many members of the P-loop family, shikimate, kinase contains a cysteine residue 2 amino acids upstream of the essential, lysine residue; the side chains of these residues are shown to form an ion, pair. The C13S mutant of shikimate kinase was found to be enzymatically, active, whereas the K15M mutant was inactive. However, the latter mutant, had both increased thermostability and affinity for ATP when compared to, the wild-type enzyme. The structure of the K15M mutant protein has been, determined at 1.8 A, and shows that the organization of the P-loop and, flanking regions is heavily disturbed. This indicates that, besides its, role in catalysis, the P-loop lysine also has an important structural, role. The structure of the K15M mutant also reveals that the formation of, an additional arginine/aspartate ion pair is the most likely reason for, its increased thermostability. From studies of ligand binding it appears, that, like adenylate kinase, shikimate kinase binds substrates randomly, and in a synergistic fashion, indicating that the two enzymes have similar, catalytic mechanisms.
About this StructureAbout this Structure
1E6C is a Single protein structure of sequence from Erwinia chrysanthemi with PO4, CL, MRD and MPD as ligands. Active as Shikimate kinase, with EC number 2.7.1.71 Structure known Active Sites: POA and POB. Full crystallographic information is available from OCA.
ReferenceReference
Biochemical and X-ray crystallographic studies on shikimate kinase: the important structural role of the P-loop lysine., Krell T, Maclean J, Boam DJ, Cooper A, Resmini M, Brocklehurst K, Kelly SM, Price NC, Lapthorn AJ, Coggins JR, Protein Sci. 2001 Jun;10(6):1137-49. PMID:11369852
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