Alteration of a novel dispensable mitochondrial ribosomal small-subunit protein, Rsm28p, allows translation of defective COX2 mRNAs.

Mutations affecting the RNA sequence of the first 10 codons of the Saccharomyces cerevisiae mitochondrial gene COX2 strongly reduce translation of the mRNA, which encodes the precursor of cytochrome c oxidase subunit II. A dominant chromosomal mutation that suppresses these defects is an internal in-frame deletion of 67 codons from the gene YDR494w. Wild-type YDR494w encodes a 361-residue polypeptide with no similarity to proteins of known function.

Regulation of the Bacillus subtilis fur and perR genes by PerR: not all members of the PerR regulon are peroxide inducible.

PerR is a ferric uptake repressor (Fur) homolog that functions as the central regulator of the inducible peroxide stress response in Bacillus subtilis. PerR has been previously demonstrated to regulate the mrgA, katA, ahpCF, hemAXCDBL, and zosA genes. We now demonstrate that PerR also mediates both the repression of its own gene and that of fur.

Mitochondrial translation of Saccharomyces cerevisiae COX2 mRNA is controlled by the nucleotide sequence specifying the pre-Cox2p leader peptide.

The mitochondrial gene encoding yeast cytochrome oxidase subunit II (Cox2p) specifies a precursor protein with a 15-amino-acid leader peptide. Deletion of the entire leader peptide coding region is known to block Cox2p accumulation posttranscriptionally. Here, we examined in vivo the role of the pre-Cox2p leader peptide and the mRNA sequence that encodes it in the expression of a mitochondrial reporter gene, ARG8m, fused to the 91st codon of COX2.

Interaction of Bacillus subtilis Fur (ferric uptake repressor) with the dhb operator in vitro and in vivo.

Bacillus subtilis contains three metalloregulatory proteins belonging to the ferric uptake repressor (Fur) family: Fur, Zur, and PerR. We have overproduced and purified Fur protein and analyzed its interaction with the operator region controlling the expression of the dihydroxybenzoate siderophore biosynthesis (dhb) operon. The purified protein binds with high affinity and selectivity to the dhb regulatory region.

Bacillus subtilis contains multiple Fur homologues: identification of the iron uptake (Fur) and peroxide regulon (PerR) repressors.

Fur (ferric uptake regulator) proteins control iron uptake in many Gram-negative bacteria. Although Fur homologues have been identified in Gram-positive bacteria, their roles in gene regulation are unknown. Genome sequencing has revealed three fur homologues in Bacillus subtilis: yqkL, yqfV and ygaG.