Control of the kilA gene of the broad-host-range plasmid RK2: involvement of korA, korB, and a new gene, korE.

AUTOR(ES)

Young, C

RESUMO

Broad-host-range plasmid RK2 encodes several different kil genes which are potentially lethal to an Escherichia coli host. The kil genes and the essential RK2 replication gene trfA are regulated by the products of kor genes. We have shown previously that kilA can be controlled by a constitutively expressed korA gene. In this study, we have found that the wild-type, autoregulated korA gene is insufficient for control of kilA cloned on high-copy-number plasmids. One of two other genes must also be present with korA. One gene is korB, originally discovered by its ability to control the determinants in the kilB region and later found to affect expression of both trfA and korA. The other is a new gene, korE, which has been cloned from the 2.2' to 4.1' region located between korC and kilA. Studies with a kilA-cat fusion suggest that korA, korB, and korE all participate in the control of kilA gene expression.

Documentos Relacionados

• Cooperativity between KorB and TrbA Repressors of Broad-Host-Range Plasmid RK2
• The kil-kor regulon of broad-host-range plasmid RK2: nucleotide sequence, polypeptide product, and expression of regulatory gene korC.
• Structural, molecular, and genetic analysis of the kilA operon of broad-host-range plasmid RK2.
• korA function of promiscuous plasmid RK2: an autorepressor that inhibits expression of host-lethal gene kilA and replication gene trfA.
• Gene control in broad host range plasmid RK2: expression, polypeptide product, and multiple regulatory functions of korB.