2i1q
From Proteopedia
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==Overview== | ==Overview== | ||
| - | Archaeal RadA or Rad51 recombinases are close homologues of eukaryal Rad51 | + | Archaeal RadA or Rad51 recombinases are close homologues of eukaryal Rad51 and DMC1. These and bacterial RecA orthologues play a key role in DNA repair by forming helical nucleoprotein filaments in which a hallmark strand exchange reaction between homologous DNA substrates occurs. Recent studies have discovered the stimulatory role by calcium on human and yeast recombinases. Here we report that the strand exchange activity but not the ATPase activity of an archaeal RadA/Rad51 recombinase from Methanococcus voltae (MvRadA) is also subject to calcium stimulation. Crystallized MvRadA filaments in the presence of CaCl(2) resemble that of the recently reported ATPase active form in the presence of an activating dose of KCl. At the ATPase center, one Ca(2+) ion takes the place of two K(+) ions in the K(+)-bound form. The terminal phosphate of the nonhydrolyzable ATP analogue is in a staggered conformation in the Ca(2+)-bound form. In comparison, an eclipsed conformation was seen in the K(+)-bound form. Despite the changes in the ATPase center, both forms harbor largely ordered L2 regions in essentially identical conformations. These data suggest a unified stimulation mechanism by potassium and calcium because of the existence of a conserved ATPase center promiscuous in binding cations. |
==About this Structure== | ==About this Structure== | ||
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[[Category: Methanococcus voltae]] | [[Category: Methanococcus voltae]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
| - | [[Category: Fodje, M | + | [[Category: Fodje, M N.]] |
[[Category: Grochulski, P.]] | [[Category: Grochulski, P.]] | ||
[[Category: He, Y.]] | [[Category: He, Y.]] | ||
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[[Category: recombinase]] | [[Category: recombinase]] | ||
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 17:48:07 2008'' |
Revision as of 15:48, 21 February 2008
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RadA Recombinase in complex with Calcium
Overview
Archaeal RadA or Rad51 recombinases are close homologues of eukaryal Rad51 and DMC1. These and bacterial RecA orthologues play a key role in DNA repair by forming helical nucleoprotein filaments in which a hallmark strand exchange reaction between homologous DNA substrates occurs. Recent studies have discovered the stimulatory role by calcium on human and yeast recombinases. Here we report that the strand exchange activity but not the ATPase activity of an archaeal RadA/Rad51 recombinase from Methanococcus voltae (MvRadA) is also subject to calcium stimulation. Crystallized MvRadA filaments in the presence of CaCl(2) resemble that of the recently reported ATPase active form in the presence of an activating dose of KCl. At the ATPase center, one Ca(2+) ion takes the place of two K(+) ions in the K(+)-bound form. The terminal phosphate of the nonhydrolyzable ATP analogue is in a staggered conformation in the Ca(2+)-bound form. In comparison, an eclipsed conformation was seen in the K(+)-bound form. Despite the changes in the ATPase center, both forms harbor largely ordered L2 regions in essentially identical conformations. These data suggest a unified stimulation mechanism by potassium and calcium because of the existence of a conserved ATPase center promiscuous in binding cations.
About this Structure
2I1Q is a Single protein structure of sequence from Methanococcus voltae with , , and as ligands. Full crystallographic information is available from OCA.
Reference
Calcium stiffens archaeal Rad51 recombinase from Methanococcus voltae for homologous recombination., Qian X, He Y, Ma X, Fodje MN, Grochulski P, Luo Y, J Biol Chem. 2006 Dec 22;281(51):39380-7. Epub 2006 Oct 17. PMID:17050545
Page seeded by OCA on Thu Feb 21 17:48:07 2008
Categories: Methanococcus voltae | Single protein | Fodje, M N. | Grochulski, P. | He, Y. | Luo, Y. | Ma, X. | Qian, X. | ANP | CA | MG | NA | Atp complex | Atpase | Calcium stimulation | Dmc1 | Rad51 | Rada | Reca | Recombinase
