View source for 1d1q

[[Image:1d1q.gif|left|200px]]<br /><applet load="1d1q" size="350" color="white" frame="true" align="right" spinBox="true" 
caption="1d1q, resolution 1.70&Aring;" />
'''CRYSTAL STRUCTURE OF A YEAST LOW MOLECULAR WEIGHT PROTEIN TYROSINE PHOSPHATASE (LTP1) COMPLEXED WITH THE SUBSTRATE PNPP'''<br />

==Overview==
Low-molecular weight protein tyrosine phosphatases are virtually ubiquitous, which implies that they have important cellular functions. We present here the 2.2 A resolution X-ray crystallographic structure of wild-type LTP1, a low-molecular weight protein tyrosine phosphatase from Saccharomyces cerevisiae. We also present the structure of an inactive mutant substrate complex of LTP1 with p-nitrophenyl phosphate (pNPP) at a resolution of 1.7 A. The crystal structures of the wild-type protein and of the inactive mutant both have two molecules per asymmetric unit. The wild-type protein crystal was grown in HEPES buffer, a sulfonate anion that resembles the phosphate substrate, and a HEPES molecule was found with nearly full occupancy in the active site. Although the fold of LTP1 resembles that of its bovine counterpart BPTP, there are significant changes around the active site that explain differences in their kinetic behavior. In the crystal of the inactive mutant of LTP1, one molecule has a pNPP in the active site, while the other has a phosphate ion. The aromatic residues lining the walls of the active site cavity exhibit large relative movements between the two molecules. The phosphate groups present in the structures of the mutant protein bind more deeply in the active site (that is, closer to the position of nucleophilic cysteine side chain) than does the sulfonate group of the HEPES molecule in the wild-type structure. This further confirms the important role of the phosphate-binding loop in stabilizing the deep binding position of the phosphate group, thus helping to bring the phosphate close to the thiolate anion of nucleophilic cysteine, and facilitating the formation of the phosphoenzyme intermediate.

==About this Structure==
1D1Q is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Saccharomyces_cerevisiae Saccharomyces cerevisiae] with <scene name='pdbligand=PO4:'>PO4</scene>, <scene name='pdbligand=4NP:'>4NP</scene> and <scene name='pdbligand=GOL:'>GOL</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Protein-tyrosine-phosphatase Protein-tyrosine-phosphatase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.1.3.48 3.1.3.48] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1D1Q OCA]. 

==Reference==
Crystal structures of a low-molecular weight protein tyrosine phosphatase from Saccharomyces cerevisiae and its complex with the substrate p-nitrophenyl phosphate., Wang S, Tabernero L, Zhang M, Harms E, Van Etten RL, Stauffacher CV, Biochemistry. 2000 Feb 29;39(8):1903-14. PMID:[http://ispc.weizmann.ac.il//pmbin/getpm?pmid=10684639 10684639]
[[Category: Protein-tyrosine-phosphatase]]
[[Category: Saccharomyces cerevisiae]]
[[Category: Single protein]]
[[Category: Etten, R L.Van.]]
[[Category: Harms, E.]]
[[Category: Staufacher, C V.]]
[[Category: Tabernero, L.]]
[[Category: Wang, S.]]
[[Category: Zhang, M.]]
[[Category: 4NP]]
[[Category: GOL]]
[[Category: PO4]]
[[Category: beta-alpha-beta]]

''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 12:12:00 2008''