1ahp: Difference between revisions

Revision as of 12:44, 21 February 2008

OLIGOSACCHARIDE SUBSTRATE BINDING IN ESCHERICHIA COLI MALTODEXTRIN PHSPHORYLASE

OverviewOverview

The crystal structure of E. coli maltodextrin phosphorylase co-crystallized with an oligosaccharide has been solved at 3.0 A resolution, providing the first structure of an oligosaccharide bound at the catalytic site of an alpha-glucan phosphorylase. An induced fit mechanism brings together two domains across the catalytic site tunnel. A stacking interaction between the glucosyl residue and the aromatic group of a tyrosine residue at a sub-site remote (8 A) from the catalytic site provides a key element in substrate recognition; mutation of this residue to Ala decreases the Kcat/Km by 10(4). Extrapolation of the results to substrate binding across the site of attack by phosphorolysis indicates a likely alteration in the glycosidic torsion angles from their preferred values, an alteration that appears to be important for the catalytic mechanism.

About this StructureAbout this Structure

1AHP is a Single protein structure of sequence from Escherichia coli with , , and as ligands. Active as Phosphorylase, with EC number 2.4.1.1 Known structural/functional Site: . Full crystallographic information is available from OCA.

ReferenceReference

Oligosaccharide substrate binding in Escherichia coli maltodextrin phosphorylase., O'Reilly M, Watson KA, Schinzel R, Palm D, Johnson LN, Nat Struct Biol. 1997 May;4(5):405-12. PMID:9145112

Page seeded by OCA on Thu Feb 21 11:44:35 2008

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OCA

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 ==Overview==
-The crystal structure of E. coli maltodextrin phosphorylase, co-crystallized with an oligosaccharide has been solved at 3.0 A, resolution, providing the first structure of an oligosaccharide bound at, the catalytic site of an alpha-glucan phosphorylase. An induced fit, mechanism brings together two domains across the catalytic site tunnel. A, stacking interaction between the glucosyl residue and the aromatic group, of a tyrosine residue at a sub-site remote (8 A) from the catalytic site, provides a key element in substrate recognition; mutation of this residue, to Ala decreases the Kcat/Km by 10(4). Extrapolation of the results to, substrate binding across the site of attack by phosphorolysis indicates a, likely alteration in the glycosidic torsion angles from their preferred, values, an alteration that appears to be important for the catalytic, mechanism.
+The crystal structure of E. coli maltodextrin phosphorylase co-crystallized with an oligosaccharide has been solved at 3.0 A resolution, providing the first structure of an oligosaccharide bound at the catalytic site of an alpha-glucan phosphorylase. An induced fit mechanism brings together two domains across the catalytic site tunnel. A stacking interaction between the glucosyl residue and the aromatic group of a tyrosine residue at a sub-site remote (8 A) from the catalytic site provides a key element in substrate recognition; mutation of this residue to Ala decreases the Kcat/Km by 10(4). Extrapolation of the results to substrate binding across the site of attack by phosphorolysis indicates a likely alteration in the glycosidic torsion angles from their preferred values, an alteration that appears to be important for the catalytic mechanism.
 ==About this Structure==
@@ Line 14: / Line 14: @@
 [[Category: Phosphorylase]]
 [[Category: Single protein]]
-[[Category: Johnson, L.N.]]
+[[Category: Johnson, L N.]]
 [[Category: Palm, D.]]
-[[Category: Reilly, M.O.]]
+[[Category: Reilly, M O.]]
 [[Category: Schinzel, R.]]
-[[Category: Watson, K.A.]]
+[[Category: Watson, K A.]]
 [[Category: GOL]]
 [[Category: MAL]]
@@ Line 31: / Line 31: @@
 [[Category: substrate]]
-''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sun Feb  3 09:30:21 2008''
+''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 11:44:35 2008''