This old version of Proteopedia is provided for student assignments while the new version is undergoing repairs. Content and edits done in this old version of Proteopedia after March 1, 2026 will eventually be lost when it is retired in about June of 2026.
Apply for new accounts at the new Proteopedia. Your logins will work in both the old and new versions.
1hd7
From Proteopedia
| Line 1: | Line 1: | ||
| - | [[Image:1hd7.jpg|left|200px]] | + | [[Image:1hd7.jpg|left|200px]] |
| - | + | ||
| - | '''A SECOND DIVALENT METAL ION IN THE ACTIVE SITE OF A NEW CRYSTAL FORM OF HUMAN APURINIC/APYRIDINIMIC ENDONUCLEASE, APE1, AND ITS IMPLICATIONS FOR THE CATALYTIC MECHANISM''' | + | {{Structure |
| + | |PDB= 1hd7 |SIZE=350|CAPTION= <scene name='initialview01'>1hd7</scene>, resolution 1.95Å | ||
| + | |SITE= <scene name='pdbsite=PB1:Pb+Binding+Site'>PB1</scene> | ||
| + | |LIGAND= <scene name='pdbligand=PB:LEAD (II) ION'>PB</scene> | ||
| + | |ACTIVITY= [http://en.wikipedia.org/wiki/DNA-(apurinic_or_apyrimidinic_site)_lyase DNA-(apurinic or apyrimidinic site) lyase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=4.2.99.18 4.2.99.18] | ||
| + | |GENE= | ||
| + | }} | ||
| + | |||
| + | '''A SECOND DIVALENT METAL ION IN THE ACTIVE SITE OF A NEW CRYSTAL FORM OF HUMAN APURINIC/APYRIDINIMIC ENDONUCLEASE, APE1, AND ITS IMPLICATIONS FOR THE CATALYTIC MECHANISM''' | ||
| + | |||
==Overview== | ==Overview== | ||
| Line 10: | Line 19: | ||
==About this Structure== | ==About this Structure== | ||
| - | 1HD7 is a [ | + | 1HD7 is a [[Single protein]] structure of sequence from [http://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1HD7 OCA]. |
==Reference== | ==Reference== | ||
| - | Two divalent metal ions in the active site of a new crystal form of human apurinic/apyrimidinic endonuclease, Ape1: implications for the catalytic mechanism., Beernink PT, Segelke BW, Hadi MZ, Erzberger JP, Wilson DM 3rd, Rupp B, J Mol Biol. 2001 Apr 6;307(4):1023-34. PMID:[http:// | + | Two divalent metal ions in the active site of a new crystal form of human apurinic/apyrimidinic endonuclease, Ape1: implications for the catalytic mechanism., Beernink PT, Segelke BW, Hadi MZ, Erzberger JP, Wilson DM 3rd, Rupp B, J Mol Biol. 2001 Apr 6;307(4):1023-34. PMID:[http://www.ncbi.nlm.nih.gov/pubmed/11286553 11286553] |
[[Category: DNA-(apurinic or apyrimidinic site) lyase]] | [[Category: DNA-(apurinic or apyrimidinic site) lyase]] | ||
[[Category: Homo sapiens]] | [[Category: Homo sapiens]] | ||
| Line 29: | Line 38: | ||
[[Category: ref-1]] | [[Category: ref-1]] | ||
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Mar 20 11:35:35 2008'' |
Revision as of 09:35, 20 March 2008
| |||||||
| , resolution 1.95Å | |||||||
|---|---|---|---|---|---|---|---|
| Sites: | |||||||
| Ligands: | |||||||
| Activity: | DNA-(apurinic or apyrimidinic site) lyase, with EC number 4.2.99.18 | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
A SECOND DIVALENT METAL ION IN THE ACTIVE SITE OF A NEW CRYSTAL FORM OF HUMAN APURINIC/APYRIDINIMIC ENDONUCLEASE, APE1, AND ITS IMPLICATIONS FOR THE CATALYTIC MECHANISM
Contents |
Overview
The major human abasic endonuclease, Ape1, is an essential DNA repair enzyme that initiates the removal of apurinic/apyrimidinic sites from DNA, excises 3' replication-blocking moieties, and modulates the DNA binding activity of several transcriptional regulators. We have determined the X-ray structure of the full-length human Ape1 enzyme in two new crystal forms, one at neutral and one at acidic pH. The new structures are generally similar to the previously determined structure of a truncated Ape1 protein, but differ in the conformation of several loop regions and in spans of residues with weak electron density. While only one active-site metal ion is present in the structure determined at low pH, the structure determined from a crystal grown at the pH optimum of Ape1 nuclease activity, pH 7.5, has two metal ions bound 5 A apart in the active site. Enzyme kinetic data indicate that at least two metal-binding sites are functionally important, since Ca(2+) exhibits complex stimulatory and inhibitory effects on the Mg(2+)-dependent catalysis of Ape1, even though Ca(2+) itself does not serve as a cofactor. In conjunction, the structural and kinetic data suggest that Ape1 catalyzes hydrolysis of the DNA backbone through a two metal ion-mediated mechanism.
Disease
Known diseases associated with this structure: Autoimmune polyglandular disease, type I OMIM:[607358], Sveinsson choreoretinal atrophy OMIM:[189967]
About this Structure
1HD7 is a Single protein structure of sequence from Homo sapiens. Full crystallographic information is available from OCA.
Reference
Two divalent metal ions in the active site of a new crystal form of human apurinic/apyrimidinic endonuclease, Ape1: implications for the catalytic mechanism., Beernink PT, Segelke BW, Hadi MZ, Erzberger JP, Wilson DM 3rd, Rupp B, J Mol Biol. 2001 Apr 6;307(4):1023-34. PMID:11286553
Page seeded by OCA on Thu Mar 20 11:35:35 2008
