chloroplasts & rho factor?

Bob Gross Robert.H.Gross at
Fri Aug 12 16:35:27 EST 1994

After some helpful hints by email, the Bionet has come through again.
It turns out that there is a gene in chloroplasts similar to rho factor
from E. coli. It is reasonable to think, therefore, that there are
probably rho termination signals used as well. Here is the reference
from Medline:

Author(s):  Oppermann T, Hong TH, Surzycki SJ
Title:  Chloroplast and nuclear genomes of Chlamydomonas reinhardtii
share homology with Escherichia coli genes for DNA replication, repair
and transcription.
Source:  Current genetics, 1989 Jan;15(1):39-46.
Abstract:  Most of the cpDNA genes studied to date are genes encoding
elements of the photosynthetic apparatus and translational machinery.
Much less is known about genes encoding the polypeptides involved in
transcription, cpDNA replication, recombination and repair. The
similarities between bacterial and some cpDNA genes  were exploited to
identify some of these chloroplast     genes using bacterial probes.
Probes derived from the Escherichia coli genes dnaA, recA, uvrC,
transcriptional factor rho, and rpoC were used to  search for
homologous DNA sequences in chloroplast and nuclear genomes of    
Chlamydomonas reinhardtii. Regions homologous to all of these genes
were located on the cpDNA physical map by probing restriction fragments
of cpDNA with plasmid fragments containing these genes. Probing nuclear
DNA with bacterial gene probes revealed DNA fragments homologous to
dnaA and rpoC genes.

Bob Gross
Dept. of Biology, Dartmouth College
bob.gross at

More information about the Methods mailing list