PcrA
PcrA (engl. plasmid copy reduced) je helikaza koja je originalno otkrivena u testiranju hromozomski kodiranih gena koji utiču na plazmidnu replikaciju u Gram-pozitivnom patogenu Staphylococcus aureus.
Biološke funkcije
Genetičke i biohemijske studije su pokazale da su helikaze esencijalne za plazmidnu replikaciju i popravku oštećenja DNK uzrokovanog izlaganjem ultraljubičastoj radijaciji. One katalizuju odplitanje dvolančane plazmidne DNK koja je bila oštećena na mestu replikacionog početka. Genetičke i biohemijske studije su takođe pokazale da helikaze doprinose preživljavanju ćelija regulacijom nivoa RecA posredovane rekombinacije Gram-pozitivnih bakterija.
Literatura
- Iordanescu S. Characterization of the Staphylococcus aureus chromosomal gene pcrA, identified by mutations affecting plasmid pT181 replication. Mol Gen Genet. 1993 Oct;241(1-2):185-92.
- Petit MA, Dervyn E, Rose M, Entian KD, McGovern S, Ehrlich SD, Bruand C. PcrA is an essential DNA helicase of Bacillus subtilis fulfilling functions both in repair and rolling-circle replication. Mol Microbiol. 1998 Jul;29(1):261-73.
- Petit MA, Ehrlich D. Essential bacterial helicases that counteract the toxicity of recombination proteins. EMBO J. 2002 Jun 17;21(12):3137-47.
- Chang TL, Naqvi A, Anand SP, Kramer MG, Munshi R, Khan SA. Biochemical characterization of the Staphylococcus aureus PcrA helicase and its role in plasmid rolling circle replication. J Biol Chem. 2002 Nov 29;277(48):45880-6. Epub 2002 Sep 19.
- Anand SP, Zheng H, Bianco PR, Leuba SH, Khan SA. DNA helicase activity of PcrA is not required for the displacement of RecA protein from DNA or inhibition of RecA-mediated strand exchange. J Bacteriol. 2007 Jun;189(12):4502-9. Epub 2007 Apr 20.
- Soultanas P, Dillingham MS, Papadopoulos F, Phillips SE, Thomas CD, Wigley DB. Plasmid replication initiator protein RepD increases the processivity of PcrA DNA helicase. Nucleic Acids Res. 1999 Mar 15;27(6):1421-8.
- Velankar SS, Soultanas P, Dillingham MS, Subramanya HS, Wigley DB. Crystal structures of complexes of PcrA DNA helicase with a DNA substrate indicate an inchworm mechanism. Cell. 1999 Apr 2;97(1):75-84.