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001-es BibID:	BIBFORM031394
035-os BibID:	PMID:15770420 WOS:000227702400007
Első szerző:	Pingoud, Alfred
Cím:	Type II restriction endonucleases : structure and mechanism / A. Pingoud, M. Fuxreiter, V. Pingoud, W. Wendea
Dátum:	2005
ISSN:	1420-682X
Megjegyzések:	Type II restriction endonucleases are components of restriction modification systems that protect bacteria and archaea against invading foreign DNA. Most are homodimeric or tetrameric enzymes that cleave DNA at defined sites of 4-8 bp in length and require Mg2+ ions for catalysis. They differ in the details of the recognition process and the mode of cleavage, indicators that these enzymes are more diverse than originally thought. Still, most of them have a similar structural core and seem to share a common mechanism of DNA cleavage, suggesting that they evolved from a common ancestor. Only a few restriction endonucleases discovered thus far do not belong to the PD...D/ExK family of enzymes, but rather have active sites typical of other endonuclease families. The present review deals with new developments in the field of Type II restriction endonucleases. One of the more interesting aspects is the increasing awareness of the diversity of Type II restriction enzymes. Nevertheless, structural studies summarized herein deal with the more common subtypes. A major emphasis of this review will be on target site location and the mechanism of catalysis, two problems currently being addressed in the literature.
Tárgyszavak:	Természettudományok Biológiai tudományok idegen nyelvű folyóiratközlemény külföldi lapban külföldön készült közlemény
Megjelenés:	Cellular and molecular life sciences. - 62 : 6 (2005), p. 685-707. -
További szerzők:	Fuxreiter Mónika (1969-) (kutató vegyész) Pingoud, Vera Wende, Wolfgang
Internet cím:	Intézményi repozitóriumban (DEA) tárolt változat DOI
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001-es BibID:	BIBFORM031395
035-os BibID:	PMID:19682999 WOS:000271341400011
Első szerző:	Pingoud, Vera
Cím:	On the divalent metal ion dependence of DNA cleavage by restriction endonucleases of the EcoRI family / Vera Pingoud, Wolfgang Wende, Peter Friedhoff, Monika Reuter, Jürgen Alves, Albert Jeltsch, Letif Mones, Monika Fuxreiter, Alfred Pingoud
Dátum:	2009
Megjegyzések:	Restriction endonucleases of the PD...D/EXK family need Mg(2+) for DNA cleavage. Whereas Mg(2+) (or Mn(2+)) promotes catalysis, Ca(2+) (without Mg(2+)) only supports DNA binding. The role of Mg(2+) in DNA cleavage by restriction endonucleases has elicited many hypotheses, differing mainly in the number of Mg(2+) involved in catalysis. To address this problem, we measured the Mg(2+) and Mn(2+) concentration dependence of DNA cleavage by BamHI, BglII, Cfr10I, EcoRI, EcoRII (catalytic domain), MboI, NgoMIV, PspGI, and SsoII, which were reported in co-crystal structure analyses to bind one (BglII and EcoRI) or two (BamHI and NgoMIV) Me(2+) per active site. DNA cleavage experiments were carried out at various Mg(2+) and Mn(2+) concentrations at constant ionic strength. All enzymes show a qualitatively similar Mg(2+) and Mn(2+) concentration dependence. In general, the Mg(2+) concentration optimum (between approximately 1 and 10 mM) is higher than the Mn(2+) concentration optimum (between approximately 0.1 and 1 mM). At still higher Mg(2+) or Mn(2+) concentrations, the activities of all enzymes tested are reduced but can be reactivated by Ca(2+). Based on these results, we propose that one Mg(2+) or Mn(2+) is critical for restriction enzyme activation, and binding of a second Me(2+) plays a role in modulating the activity. Steady-state kinetics carried out with EcoRI and BamHI suggest that binding of a second Mg(2+) or Mn(2+) mainly leads to an increase in K(m), such that the inhibitory effect of excess Mg(2+) or Mn(2+) can be overcome by increasing the substrate concentration. Our conclusions are supported by molecular dynamics simulations and are consistent with the structural observations of both one and two Me(2+) binding to these enzymes.
Tárgyszavak:	Természettudományok Biológiai tudományok idegen nyelvű folyóiratközlemény külföldi lapban külföldön készült közlemény
Megjelenés:	Journal of molecular biology. - 393 : 1 (2009), p. 140-160. -
További szerzők:	Wende, Wolfgang Friedhoff, Peter Reuter Mónika Alves, Jürgen Jeltsch, Albert Mones, Letif Fuxreiter Mónika (1969-) (kutató vegyész) Pingoud, Alfred
Internet cím:	Intézményi repozitóriumban (DEA) tárolt változat DOI
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