Dependence upon growth medium and the polA, polC, recA, recB, recC, and exrA genes of separate branches of the uvr gene-dependent excision-repair process in Escherichia coli K12 cells

Conference · Tue Dec 31 23:00:00 EST 1974

OSTI ID:4126008

Smith, K C; Youngs, D A; Van der Schueren, E; Hanawalt, P C ^[1]

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1. ed.

The repair of single-strand breaks which arise in DNA during the uvr gene-dependent excision-repair process was examined in certain radiation- sensitive strains of Escherichia coli K12. The results suggest that the excision- repair process may be divided into two branches, one which is dependent on the presence of growth medium and also the rec$sup +$ exr$sup +$ genotype, and a second which can occur in buffer (growth medium independent) and is largely dependent on DNA polymerase I. DNA polymerase III appears to be involved in the growth-medium-dependent branch of excision repair, and also in the residual growth-medium-independent repair which occurs in polA1 cells. Chloramphenicol, dinitrophenol, and impurities present in some brands of agar all appear to inhibit the growth-medium-dependent branch of excision-repair. The similarities of the two branches of excision-repair to two known pathways for the repair of x- ray-induced DNA chain breaks are discussed. (auth)

• Research Organization: Stanford Univ. School of Medicine, CA
• NSA Number: NSA-33-012289
• OSTI ID: 4126008
• Country of Publication: United States
• Language: English

Related Subjects

*CHLORAMPHENICOL-- BIOLOGICAL EFFECTS
*DINITROPHENOL-- BIOLOGICAL EFFECTS
*DNA-- STRAND BREAKS
*ESCHERICHIA COLI-- BIOLOGICAL RADIATION EFFECTS
560131* --Biomedical Sciences
Applied Studies--Radiation Effects--Radiation Effects on Microorganisms--Basic Studies
N48110 --Life Sciences--Radiation Effects on Biochemicals--In-Vitro
N48310* --Life Sciences--Radiation Effects on Microorganisms- -Basic Studies
POLYMERASES
ULTRAVIOLET RADIATION