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 5 mM 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.
|Number of pages
|Biochemical and Biophysical Research Communications
|Published - 2007 Jun 8
Bibliographical noteFunding Information:
This work was supported by a grant from the Ministry of Science and Technology, Republic of Korea through the 21C Frontier Microbial Genomics and Applications Center Program and by a grant from KOSEF through AEBRC at POSTECH. K.C. is a recipient of the Brain Korea 21 scholarship. G.J.Z. acknowledges the support of NSF through grants MCB-0078465 and CHE-0221978.
All Science Journal Classification (ASJC) codes
- Molecular Biology
- Cell Biology