Requirement of duplicated operons for maximal metabolism of phthalate by Rhodococcus sp. strain DK17.
The operons encoding the transformation of phthalate to protocatechuate are duplicated and present on two different megaplasmids [pDK2 (330 kb) and pDK3 (750 kb)] in Rhodococcus sp. strain DK17. RT-PCR experiments using gene-specific primers showed that both the pDK2- and the pDK3-encoded dihydroxyphthalate decarboxylase genes are simultaneously expressed during growth on phthalate. The doubling time of the pDK2-cured mutant strain DK176 in minimal liquid medium with 5mM phthalate is 52.5% of that of the wild-type strain DK17. The data indicate that both copies of the phthalate operon are equally functional in DK17, and gene dosage is the main reason for slower growth of DK176 on phthalate.
Choi
Ki Young
KY
Department of Biology, Yonsei University, Seoul 120-749, Republic of Korea.
Kim
Dockyu
D
Chae
Jong-Chan
JC
Zylstra
Gerben J
GJ
Kim
Eungbin
E
D002262:Carboxy-Lyases / Q000235:genetics / Q000378:metabolism; D002455:Cell Division / Q000187:drug effects / Q000235:genetics / Q000502:physiology; D020440:Gene Duplication; D015964:Gene Expression Regulation, Bacterial / Q000187:drug effects; D023061:Gene Order; D005798:Genes, Bacterial; D053858:Metabolic Networks and Pathways; D009154:Mutation; D009876:Operon / Q000235:genetics*; D010795:Phthalic Acids / Q000378:metabolism* / Q000494:pharmacology; D010957:Plasmids / Q000235:genetics; D012240:Rhodococcus / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*
D010795:Phthalic Acids; C032279:phthalic acid; D002262:Carboxy-Lyases; C020056:4,5-dihydroxyphthalate decarboxylase