Copy mutants of plasmid R1: effects of base pair substitutions in the copA gene on the replication control system

TY - JOUR

T1 - Copy mutants of plasmid R1

T2 - effects of base pair substitutions in the copA gene on the replication control system

AU - Givskov, M

AU - Molin, Søren

PY - 1984

Y1 - 1984

N2 - Five different copA copy mutants of plasmid R1 have been identified by nucleotide sequencing. Independent measurements of the activities of the mutant inhibitor RNA and of the mutant target properties were carried out using several different methods. Correlation of these measurements with the location of th nucleotide substitutions resulted in the following conclusions: (1) The copy number of plasmid R1 is controlled primarily by interaction between the CopA RNA molecule and its target, the RepA mRNA. (2) The binding of th inhibitor to its target is based on nucleotide interactions within two complementary sequences of ten nucleotides and dependent on the secondary structure of the active site. (3) The secondary structure of both the CopA target and the CopA RNA is a stem-loop structure. Mutations in the loop region interfere with binding affinity between inhibitor and target, whereas mutations in the upper stem mainly interfere with secondary structure. Mutations in the latter region create temperature-dependent copy number phenotypes.

AB - Five different copA copy mutants of plasmid R1 have been identified by nucleotide sequencing. Independent measurements of the activities of the mutant inhibitor RNA and of the mutant target properties were carried out using several different methods. Correlation of these measurements with the location of th nucleotide substitutions resulted in the following conclusions: (1) The copy number of plasmid R1 is controlled primarily by interaction between the CopA RNA molecule and its target, the RepA mRNA. (2) The binding of th inhibitor to its target is based on nucleotide interactions within two complementary sequences of ten nucleotides and dependent on the secondary structure of the active site. (3) The secondary structure of both the CopA target and the CopA RNA is a stem-loop structure. Mutations in the loop region interfere with binding affinity between inhibitor and target, whereas mutations in the upper stem mainly interfere with secondary structure. Mutations in the latter region create temperature-dependent copy number phenotypes.

M3 - Journal article

C2 - 6203014

SN - 0026-8925

VL - 194

SP - 286

EP - 292

JO - Molecular and General Genetics MGG

JF - Molecular and General Genetics MGG

IS - 1-2

ER -