1e6c: Difference between revisions

Revision as of 13:24, 21 February 2008

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 , , and as ligands. Active as Shikimate kinase, with EC number 2.7.1.71 Known structural/functional Sites: and . 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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 ==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 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.
+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==
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 [[Category: Shikimate kinase]]
 [[Category: Single protein]]
-[[Category: Coggins, J.R.]]
+[[Category: Coggins, J R.]]
 [[Category: Krell, T.]]
-[[Category: Lapthorn, A.J.]]
+[[Category: Lapthorn, A J.]]
 [[Category: Maclean, J.]]
 [[Category: CL]]
@@ Line 29: / Line 29: @@
 [[Category: transferase]]
-''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sun Feb  3 09:37:40 2008''
+''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 12:24:18 2008''