1: Biochim Biophys Acta. 2005 Feb 14;1727(2):87-96. Epub 2004 Dec 31.

The YrdC protein--a putative ribosome maturation factor.

Kaczanowska M, Rydén-Aulin M.

Department of Genetics, Microbiology and Toxicology (GMT), University of
Stockholm, S-106 91 Stockholm, Sweden.

Release factor one (RF1) terminates protein synthesis in response to stop codons 
UAG and UAA. A mutant allele of RF1 causes temperature sensitive growth at 42
degrees C. We have earlier described the isolation of a suppressor of the
temperature sensitive phenotype. The suppressor mutation is a small deletion in
the open reading frame yrdC, and we have shown that the DeltayrdC mutation leads 
to immature 30S subunits and, as a consequence, to fewer translating ribosomes.
YrdC is a small conserved protein with a dsRNA-binding surface. Here, we have
characterized the YrdC protein. We show that the deletion leads to no production 
of functional protein, and we have indications that the YrdC protein might be
essential in a wild type background. The protein is needed for the maturation of 
16S rRNA, even though it does not interact tightly with either of the ribosomal
subunits, or the 70S particles. The less effective maturation of rRNA affects the
ribosomal feedback control, leading to an increase in expression from P1rrnB. We 
suggest that the function of the YrdC protein is to keep an rRNA structure needed
for proper processing of 16S rRNA, especially at lower temperatures. This
activity may require other factor(s). We suggest the gene be renamed rimN, and
the mutant allele rimN141.


PMID: 15716138 [PubMed - indexed for MEDLINE]

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