1eyf
From Proteopedia
| Line 1: | Line 1: | ||
[[Image:1eyf.jpg|left|200px]] | [[Image:1eyf.jpg|left|200px]] | ||
| - | + | <!-- | |
| - | + | The line below this paragraph, containing "STRUCTURE_1eyf", creates the "Structure Box" on the page. | |
| - | + | You may change the PDB parameter (which sets the PDB file loaded into the applet) | |
| - | + | or the SCENE parameter (which sets the initial scene displayed when the page is loaded), | |
| - | | | + | or leave the SCENE parameter empty for the default display. |
| - | | | + | --> |
| - | + | {{STRUCTURE_1eyf| PDB=1eyf | SCENE= }} | |
| - | + | ||
| - | + | ||
| - | }} | + | |
'''REFINED STRUCTURE OF THE DNA METHYL PHOSPHOTRIESTER REPAIR DOMAIN OF E. COLI ADA''' | '''REFINED STRUCTURE OF THE DNA METHYL PHOSPHOTRIESTER REPAIR DOMAIN OF E. COLI ADA''' | ||
| Line 33: | Line 30: | ||
[[Category: Wagner, G.]] | [[Category: Wagner, G.]] | ||
[[Category: Wintner, T.]] | [[Category: Wintner, T.]] | ||
| - | [[Category: | + | [[Category: One central beta-sheet sandwiched between two alpha-helice]] |
| - | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Fri May 2 15:40:09 2008'' | |
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | + | |
Revision as of 12:40, 2 May 2008
REFINED STRUCTURE OF THE DNA METHYL PHOSPHOTRIESTER REPAIR DOMAIN OF E. COLI ADA
Overview
The Escherichia coli protein Ada specifically repairs the S(p) diastereomer of DNA methyl phosphotriesters in DNA by direct and irreversible transfer of the methyl group to its own Cys 69 which is part of a zinc-thiolate center. The methyl transfer converts Ada into a transcriptional activator that binds sequence-specifically to promoter regions of its own gene and other methylation resistance genes. Ada thus acts as a chemosensor to activate repair mechanisms in situations of methylation damage. Here we present a highly refined solution structure of the 10 kDa N-terminal domain, N-Ada10, which reveals structural details of the nonspecific DNA interaction of N-Ada10 during the repair process and provides a basis for understanding the mechanism of the conformational switch triggered by methyl transfer. To further elucidate this, EXAFS (extended X-ray absorption fine structure) and XANES (X-ray absorption near-edge structure) data were acquired, which confirmed that the zinc-thiolate center is maintained when N-Ada is methylated. Thus, ligand exchange is not the mechanism that enhances sequence-specific DNA binding and transcriptional activation upon methylation of N-Ada. The mechanism of the switch was further elucidated by recording NOESY spectra of specifically labeled methylated-Ada/DNA complexes, which showed that the transferred methyl group makes many contacts within N-Ada but none with the DNA. This implies that methylation of N-Ada induces a structural change, which enhances the promoter affinity of a remodeled surface region that does not include the transferred methyl group.
About this Structure
1EYF is a Single protein structure of sequence from Escherichia coli. Full crystallographic information is available from OCA.
Reference
Structural basis for the functional switch of the E. coli Ada protein., Lin Y, Dotsch V, Wintner T, Peariso K, Myers LC, Penner-Hahn JE, Verdine GL, Wagner G, Biochemistry. 2001 Apr 10;40(14):4261-71. PMID:11284682 Page seeded by OCA on Fri May 2 15:40:09 2008
