1n7n: Difference between revisions

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Streptococcus pneumoniae Hyaluronate Lyase W292A Mutant

OverviewOverview

Streptococcus pneumoniae hyaluronate lyase is a surface antigen of this Gram-positive human bacterial pathogen. The primary function of this enzyme is the degradation of hyaluronan, which is a major component of the extracellular matrix of the tissues of vertebrates and of some bacteria. The enzyme degrades its substrate through a beta-elimination process called proton acceptance and donation. The inherent part of this degradation is a processive mode of action of the enzyme degrading hyaluronan into unsaturated disaccharide hyaluronic acid blocks from the reducing to the nonreducing end of the polymer following the initial random endolytic binding to the substrate. The final degradation product is the unsaturated disaccharide hyaluronic acid. The residues of the enzyme that are involved in various aspects of such degradation were identified based on the three-dimensional structures of the native enzyme and its complexes with hyaluronan substrates of various lengths. The catalytic residues were identified to be Asn(349), His(399), and Tyr(408). The residues responsible for the release of the product of the reaction were identified as Glu(388), Asp(398), and Thr(400), and they were termed negative patch. The hydrophobic residues Trp(291), Trp(292), and Phe(343) were found to be responsible for the precise positioning of the substrate for enzyme catalysis and named hydrophobic patch. The comparison of the specific activities and kinetic properties of the wild type and the mutant enzymes involving the hydrophobic patch residues W292A, F343V, W291A/W292A, W292A/F343V, and W291A/W292A/F343V allowed for the characterization of every mutant and for the correlation of the activity and kinetic properties of the enzyme with its structure as well as the mechanism of catalysis.

About this StructureAbout this Structure

1N7N is a Single protein structure of sequence from Streptococcus pneumoniae. Active as Hyaluronate lyase, with EC number 4.2.2.1 Full crystallographic information is available from OCA.

ReferenceReference

The function of hydrophobic residues in the catalytic cleft of Streptococcus pneumoniae hyaluronate lyase. Kinetic characterization of mutant enzyme forms., Nukui M, Taylor KB, McPherson DT, Shigenaga MK, Jedrzejas MJ, J Biol Chem. 2003 Jan 31;278(5):3079-88. Epub 2002 Nov 21. PMID:12446724

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 '''Streptococcus pneumoniae Hyaluronate Lyase W292A Mutant'''<br />
 ==Overview==
-Streptococcus pneumoniae hyaluronate lyase is a surface antigen of this, Gram-positive human bacterial pathogen. The primary function of this, enzyme is the degradation of hyaluronan, which is a major component of the, extracellular matrix of the tissues of vertebrates and of some bacteria., The enzyme degrades its substrate through a beta-elimination process, called proton acceptance and donation. The inherent part of this, degradation is a processive mode of action of the enzyme degrading, hyaluronan into unsaturated disaccharide hyaluronic acid blocks from the, reducing to the nonreducing end of the polymer following the initial, random endolytic binding to the substrate. The final degradation product, is the unsaturated disaccharide hyaluronic acid. The residues of the, enzyme that are involved in various aspects of such degradation were, identified based on the three-dimensional structures of the native enzyme, and its complexes with hyaluronan substrates of various lengths. The, catalytic residues were identified to be Asn(349), His(399), and Tyr(408)., The residues responsible for the release of the product of the reaction, were identified as Glu(388), Asp(398), and Thr(400), and they were termed, negative patch. The hydrophobic residues Trp(291), Trp(292), and Phe(343), were found to be responsible for the precise positioning of the substrate, for enzyme catalysis and named hydrophobic patch. The comparison of the, specific activities and kinetic properties of the wild type and the mutant, enzymes involving the hydrophobic patch residues W292A, F343V, W291A/W292A, W292A/F343V, and W291A/W292A/F343V allowed for the, characterization of every mutant and for the correlation of the activity, and kinetic properties of the enzyme with its structure as well as the, mechanism of catalysis.
+Streptococcus pneumoniae hyaluronate lyase is a surface antigen of this Gram-positive human bacterial pathogen. The primary function of this enzyme is the degradation of hyaluronan, which is a major component of the extracellular matrix of the tissues of vertebrates and of some bacteria. The enzyme degrades its substrate through a beta-elimination process called proton acceptance and donation. The inherent part of this degradation is a processive mode of action of the enzyme degrading hyaluronan into unsaturated disaccharide hyaluronic acid blocks from the reducing to the nonreducing end of the polymer following the initial random endolytic binding to the substrate. The final degradation product is the unsaturated disaccharide hyaluronic acid. The residues of the enzyme that are involved in various aspects of such degradation were identified based on the three-dimensional structures of the native enzyme and its complexes with hyaluronan substrates of various lengths. The catalytic residues were identified to be Asn(349), His(399), and Tyr(408). The residues responsible for the release of the product of the reaction were identified as Glu(388), Asp(398), and Thr(400), and they were termed negative patch. The hydrophobic residues Trp(291), Trp(292), and Phe(343) were found to be responsible for the precise positioning of the substrate for enzyme catalysis and named hydrophobic patch. The comparison of the specific activities and kinetic properties of the wild type and the mutant enzymes involving the hydrophobic patch residues W292A, F343V, W291A/W292A, W292A/F343V, and W291A/W292A/F343V allowed for the characterization of every mutant and for the correlation of the activity and kinetic properties of the enzyme with its structure as well as the mechanism of catalysis.
 ==About this Structure==
-N7N is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Streptococcus_pneumoniae Streptococcus pneumoniae]. Active as [http://en.wikipedia.org/wiki/Hyaluronate_lyase Hyaluronate lyase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=4.2.2.1 4.2.2.1] Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=1N7N OCA].
+N7N is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Streptococcus_pneumoniae Streptococcus pneumoniae]. Active as [http://en.wikipedia.org/wiki/Hyaluronate_lyase Hyaluronate lyase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=4.2.2.1 4.2.2.1] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1N7N OCA].
 ==Reference==
@@ Line 14: / Line 14: @@
 [[Category: Single protein]]
 [[Category: Streptococcus pneumoniae]]
-[[Category: Jedrzejas, M.J.]]
+[[Category: Jedrzejas, M J.]]
-[[Category: McPherson, D.T.]]
+[[Category: McPherson, D T.]]
 [[Category: Nukui, M.]]
 [[Category: Shigenaga, M.]]
-[[Category: Taylor, K.B.]]
+[[Category: Taylor, K B.]]
 [[Category: protein mutant]]
-''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on Tue Nov 20 22:01:31 2007''
+''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 14:03:11 2008''