Recombinase A: Difference between revisions

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== RecA and Hofmeister Salts ==
== RecA and Hofmeister Salts ==
High salt concentrations have also been shown to be able to elongate the RecA protein filament as well. Petukhov et al. demonstrated that a high concentration of NaCl increased the helical pitch from 7.8 to 8.6 nm.<ref name=Peukhov> Peukhov, M.; Lebedev, D.; Shalguev, V.; Islamov, A.; Kruklin, A.; Lanzov, V.; Isaev-Ivanov, V. Conformational Flexibility of RecA Protein Filament: Transitions between Compressed and Stretched States. Proteins: Struct.,Funct., Bioinf. 2006,65, 296-304. DOI: 10.1002/prot.21116 </ref> Thus, high salt concentrations appear to induce the active (stretched) form of RecA in the absence of DNA.<ref name=Peukhov> Peukhov, M.; Lebedev, D.; Shalguev, V.; Islamov, A.; Kruklin, A.; Lanzov, V.; Isaev-Ivanov, V. Conformational Flexibility of RecA Protein Filament: Transitions between Compressed and Stretched States. Proteins: Struct.,Funct., Bioinf. 2006,65, 296-304. DOI: 10.1002/prot.21116 </ref>  Other studies have found that the free Magnesium ion binds to RecA and extends the filament more than 150% compared to the filament when DNA is bound.<ref name=Roca> Roca, A. I.; Cox, M. M. RecA Protein: Structure, Function, and Role in Recombinational DNA Repair. Prog. Nucleic Acid Res. Mol. Biol. 1997, 56, 129-223. DOI: 10.1016/S0079-6603(08)61005-3 </ref> ''' {Lusetti}'''  Moreover, although normally RecA requires DNA to hydrolyze ATP, high salt concentrations are able to stimulate ATP hydrolysis in the absence of DNA.<ref name=Roca> Roca, A. I.; Cox, M. M. RecA Protein: Structure, Function, and Role in Recombinational DNA Repair. Prog. Nucleic Acid Res. Mol. Biol. 1997, 56, 129-223. DOI: 10.1016/S0079-6603(08)61005-3 </ref> ''' k17'''  Brenner and Zlotnick reported that the presence of monovalent salts changed the distribution of RecA aggregation states and that the more aggregated structures corresponded to higher protein concentration.<ref name=Brenner> Brenner, S. L.; Zlotnick, A. RecA Protein Self-assembly: Multiple Discrete Aggregation States. J. Mol. Biol. 1988, 204, 959-972. DOI: 10.1016/0022-2836(88)90055-1 </ref>  Previous studies have shown that various Hofmeister salts affect the secondary structure, stability, and aggregation behavior of RecA differently.<ref name=Brenner> Brenner, S. L.; Zlotnick, A. RecA Protein Self-assembly: Multiple Discrete Aggregation States. J. Mol. Biol. 1988, 204, 959-972. DOI: 10.1016/0022-2836(88)90055-1 </ref> <ref name=Roca> Roca, A. I.; Cox, M. M. RecA Protein: Structure, Function, and Role in Recombinational DNA Repair. Prog. Nucleic Acid Res. Mol. Biol. 1997, 56, 129-223. DOI: 10.1016/S0079-6603(08)61005-3 </ref>  '''T12'''  Additionally, RecA has been demonstrated to follow the inverse-anionic Hofmeister series and the presence of some ions promotes nonspecific aggregation.<ref name=Roca> Roca, A. I.; Cox, M. M. RecA Protein: Structure, Function, and Role in Recombinational DNA Repair. Prog. Nucleic Acid Res. Mol. Biol. 1997, 56, 129-223. DOI: 10.1016/S0079-6603(08)61005-3 </ref>  '''T12'''
High salt concentrations have also been shown to be able to elongate the RecA protein filament as well. Petukhov et al. demonstrated that a high concentration of NaCl increased the helical pitch from 7.8 to 8.6 nm.<ref name=Peukhov> Peukhov, M.; Lebedev, D.; Shalguev, V.; Islamov, A.; Kruklin, A.; Lanzov, V.; Isaev-Ivanov, V. Conformational Flexibility of RecA Protein Filament: Transitions between Compressed and Stretched States. Proteins: Struct.,Funct., Bioinf. 2006,65, 296-304. DOI: 10.1002/prot.21116 </ref> Thus, high salt concentrations appear to induce the active (stretched) form of RecA in the absence of DNA.<ref name=Peukhov> Peukhov, M.; Lebedev, D.; Shalguev, V.; Islamov, A.; Kruklin, A.; Lanzov, V.; Isaev-Ivanov, V. Conformational Flexibility of RecA Protein Filament: Transitions between Compressed and Stretched States. Proteins: Struct.,Funct., Bioinf. 2006,65, 296-304. DOI: 10.1002/prot.21116 </ref>  Other studies have found that the free Magnesium ion binds to RecA and extends the filament more than 150% compared to the filament when DNA is bound.<ref name=Lusetti> Lusetti, S. L.; Shaw, J. J.; Cox, M. M. Magnesium Ion-dependent Activation of the RecA Protein
Involves the C Terminus. J. Biol. Chem. 2003, 278, 16381–16388. DOI: 10.1074/jbc.M212916200 </ref> Moreover, although normally RecA requires DNA to hydrolyze ATP, high salt concentrations are able to stimulate ATP hydrolysis in the absence of DNA.<ref name=Roca> Roca, A. I.; Cox, M. M. RecA Protein: Structure, Function, and Role in Recombinational DNA Repair. Prog. Nucleic Acid Res. Mol. Biol. 1997, 56, 129-223. DOI: 10.1016/S0079-6603(08)61005-3 </ref> ''' k17'''  Brenner and Zlotnick reported that the presence of monovalent salts changed the distribution of RecA aggregation states and that the more aggregated structures corresponded to higher protein concentration.<ref name=Brenner> Brenner, S. L.; Zlotnick, A. RecA Protein Self-assembly: Multiple Discrete Aggregation States. J. Mol. Biol. 1988, 204, 959-972. DOI: 10.1016/0022-2836(88)90055-1 </ref>  Previous studies have shown that various Hofmeister salts affect the secondary structure, stability, and aggregation behavior of RecA differently.<ref name=Brenner> Brenner, S. L.; Zlotnick, A. RecA Protein Self-assembly: Multiple Discrete Aggregation States. J. Mol. Biol. 1988, 204, 959-972. DOI: 10.1016/0022-2836(88)90055-1 </ref> <ref name=Roca> Roca, A. I.; Cox, M. M. RecA Protein: Structure, Function, and Role in Recombinational DNA Repair. Prog. Nucleic Acid Res. Mol. Biol. 1997, 56, 129-223. DOI: 10.1016/S0079-6603(08)61005-3 </ref>  '''T12'''  Additionally, RecA has been demonstrated to follow the inverse-anionic Hofmeister series and the presence of some ions promotes nonspecific aggregation.<ref name=Roca> Roca, A. I.; Cox, M. M. RecA Protein: Structure, Function, and Role in Recombinational DNA Repair. Prog. Nucleic Acid Res. Mol. Biol. 1997, 56, 129-223. DOI: 10.1016/S0079-6603(08)61005-3 </ref>  '''T12'''


== References ==
== References ==

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