2jhj: Difference between revisions
From Proteopedia
Jump to navigationJump to search
No edit summary |
No edit summary |
||
| Line 5: | Line 5: | ||
==Overview== | ==Overview== | ||
N(1)-methyladenine (m(1)A) and N(3)-methylcytosine (m(3)C) are major toxic, and mutagenic lesions induced by alkylation in single-stranded DNA. In, bacteria and mammals, m(1)A and m(3)C were recently shown to be repaired, by AlkB-mediated oxidative demethylation, a direct DNA damage reversal, mechanism. No AlkB gene homologues have been identified in Archaea. We, report that m(1)A and m(3)C are repaired by the AfAlkA base excision, repair glycosylase of Archaeoglobus fulgidus, suggesting a different, repair mechanism for these lesions in the third domain of life. In, addition, AfAlkA was found to effect a robust excision of, 1,N(6)-ethenoadenine. We present a high-resolution crystal structure of, AfAlkA, which, together with the characterization of several site-directed, mutants, forms a . | N(1)-methyladenine (m(1)A) and N(3)-methylcytosine (m(3)C) are major toxic, and mutagenic lesions induced by alkylation in single-stranded DNA. In, bacteria and mammals, m(1)A and m(3)C were recently shown to be repaired, by AlkB-mediated oxidative demethylation, a direct DNA damage reversal, mechanism. No AlkB gene homologues have been identified in Archaea. We, report that m(1)A and m(3)C are repaired by the AfAlkA base excision, repair glycosylase of Archaeoglobus fulgidus, suggesting a different, repair mechanism for these lesions in the third domain of life. In, addition, AfAlkA was found to effect a robust excision of, 1,N(6)-ethenoadenine. We present a high-resolution crystal structure of, AfAlkA, which, together with the characterization of several site-directed, mutants, forms a molecular rationalization for the newly discovered base, excision activity. | ||
==About this Structure== | ==About this Structure== | ||
2JHJ is a | 2JHJ is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Archaeoglobus_fulgidus Archaeoglobus fulgidus] with NA and GOL as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/DNA-3-methyladenine_glycosylase_II DNA-3-methyladenine glycosylase II], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.2.2.21 3.2.2.21] Structure known Active Site: AC1. Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=2JHJ OCA]. | ||
==Reference== | ==Reference== | ||
| Line 40: | Line 40: | ||
[[Category: n3-methylcytosine]] | [[Category: n3-methylcytosine]] | ||
''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on | ''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on Mon Nov 5 14:27:57 2007'' | ||
