5pnt
From Proteopedia
(New page: 200px<br /> <applet load="5pnt" size="450" color="white" frame="true" align="right" spinBox="true" caption="5pnt, resolution 2.2Å" /> '''CRYSTAL STRUCTURE OF...) |
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| - | [[Image:5pnt.gif|left|200px]]<br /> | + | [[Image:5pnt.gif|left|200px]]<br /><applet load="5pnt" size="350" color="white" frame="true" align="right" spinBox="true" |
| - | <applet load="5pnt" size=" | + | |
caption="5pnt, resolution 2.2Å" /> | caption="5pnt, resolution 2.2Å" /> | ||
'''CRYSTAL STRUCTURE OF A HUMAN LOW MOLECULAR WEIGHT PHOSPHOTYROSYL PHOSPHATASE. IMPLICATIONS FOR SUBSTRATE SPECIFICITY'''<br /> | '''CRYSTAL STRUCTURE OF A HUMAN LOW MOLECULAR WEIGHT PHOSPHOTYROSYL PHOSPHATASE. IMPLICATIONS FOR SUBSTRATE SPECIFICITY'''<br /> | ||
==Overview== | ==Overview== | ||
| - | The low molecular weight phosphotyrosine phosphatases (PTPases) constitute | + | The low molecular weight phosphotyrosine phosphatases (PTPases) constitute a distinctive class of phosphotyrosine phosphatases that is widely distributed among vertebrate and invertebrate organisms. In vertebrates, two isoenzymes of these low molecular weight PTPases are commonly expressed. The two human isoenzymes, HCPTPA and HCPTPB, differ in an alternatively spliced sequence (residues 40-73) referred to as the variable loop, resulting in isoenzymes that have different substrate specificities and inhibitor/activator responses. We present here the x-ray crystallographic structure of a human low molecular weight PTPase solved by molecular replacement to 2.2 A. The structure of human low molecular weight PTPase is compared with a structure representing the other isoenzyme in this PTPase class, in each case with a sulfonate inhibitor bound to the active site. Possible aromatic residue interactions with the phosphotyrosine substrate are proposed from an examination of the binding site of the inhibitors. Differences are observed in the variable loop region, which forms one wall and the floor of a long crevice leading from the active-site loop. A set of residues lying along this crevice (amino acids 49, 50, and 53) is suggested to be responsible for differences in substrate specificity in these two enzymes. |
==About this Structure== | ==About this Structure== | ||
| - | 5PNT is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens] with MES as [http://en.wikipedia.org/wiki/ligand ligand]. Active as [http://en.wikipedia.org/wiki/Acid_phosphatase Acid phosphatase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.1.3.2 3.1.3.2] Full crystallographic information is available from [http:// | + | 5PNT is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens] with <scene name='pdbligand=MES:'>MES</scene> as [http://en.wikipedia.org/wiki/ligand ligand]. Active as [http://en.wikipedia.org/wiki/Acid_phosphatase Acid phosphatase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.1.3.2 3.1.3.2] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=5PNT OCA]. |
==Reference== | ==Reference== | ||
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[[Category: tyrosine phosphatase]] | [[Category: tyrosine phosphatase]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 19:15:40 2008'' |
Revision as of 17:15, 21 February 2008
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CRYSTAL STRUCTURE OF A HUMAN LOW MOLECULAR WEIGHT PHOSPHOTYROSYL PHOSPHATASE. IMPLICATIONS FOR SUBSTRATE SPECIFICITY
Overview
The low molecular weight phosphotyrosine phosphatases (PTPases) constitute a distinctive class of phosphotyrosine phosphatases that is widely distributed among vertebrate and invertebrate organisms. In vertebrates, two isoenzymes of these low molecular weight PTPases are commonly expressed. The two human isoenzymes, HCPTPA and HCPTPB, differ in an alternatively spliced sequence (residues 40-73) referred to as the variable loop, resulting in isoenzymes that have different substrate specificities and inhibitor/activator responses. We present here the x-ray crystallographic structure of a human low molecular weight PTPase solved by molecular replacement to 2.2 A. The structure of human low molecular weight PTPase is compared with a structure representing the other isoenzyme in this PTPase class, in each case with a sulfonate inhibitor bound to the active site. Possible aromatic residue interactions with the phosphotyrosine substrate are proposed from an examination of the binding site of the inhibitors. Differences are observed in the variable loop region, which forms one wall and the floor of a long crevice leading from the active-site loop. A set of residues lying along this crevice (amino acids 49, 50, and 53) is suggested to be responsible for differences in substrate specificity in these two enzymes.
About this Structure
5PNT is a Single protein structure of sequence from Homo sapiens with as ligand. Active as Acid phosphatase, with EC number 3.1.3.2 Full crystallographic information is available from OCA.
Reference
Crystal structure of a human low molecular weight phosphotyrosyl phosphatase. Implications for substrate specificity., Zhang M, Stauffacher CV, Lin D, Van Etten RL, J Biol Chem. 1998 Aug 21;273(34):21714-20. PMID:9705307
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