High impact information on petD

• The middle part of the Tbc2 protein displays partial amino acid sequence identity with Crp1, a protein from Zea mays that is implicated in the processing and translation of the chloroplast petA and petD RNAs [1].
• This includes the mitochondrial coxI intron i1 from the fungus Podospora anserina, the plastid petD intron from the alga Scenedesmus obliquus and the mitochondrial RTL gene from the alga Chlamydomonas reinhardtii [2].
• The chloroplast petD gene encodes subunit IV of the cytochrome b6/f complex and is required for photosynthetic electron transport [3].
• We have created Chlamydomonas strains in which the initiation codon of the petD gene has been changed to AUU or AUC [3].
• Our results show that sequences essential for translation reside in the petD 5' UTR and also that sequences within the 5' UTR directly or indirectly affect mRNA stability [4].

Biological context of petD

• Sequences of trnR-ACG and petD that contain a tRNA-like element within the chloroplast genome of Chlamydomonas reinhardtii [5].
• Nucleotide sequences of the continuous and separated petA, petB and petD chloroplast genes in Chlamydomonas reinhardtii [6].
• In vivo analysis of Chlamydomonas chloroplast petD gene expression using stable transformation of beta-glucuronidase translational fusions [4].
• The insertion of a polyguanosine sequence into the petD 5' UTR fused to a reporter gene allowed accumulation of the reporter gene transcript in the mutant background [7].
• We previously reported that these mutants fail to accumulate the chloroplast petD mRNA and its product, subunit IV of the cytochrome b6/f complex, which is essential for photosynthesis [8].

Other interactions of petD

• At variance with the pet genes in higher plant chloroplasts, the petB and petD genes are continuous, not adjacent and not located next to the psbB gene [6].
• These inversions created a functional chimeric petD gene that includes the promoter and part of the 5' UTR of the newly identified ycf9-psbM transciption unit, fused to the petD 5' UTR upstream of the FUD6 deletion [9].
• Three classes of RNA, represented by atpB and petD mRNAs, Arg and Glu tRNAs, and 5S rRNA, were found to exist in polyadenylated form in Chlamydomonas reinhardtii chloroplasts [10].
• In mcd1 mutants, which are non-photosynthetic, petD mRNA is degraded by a 5'-3' exonuclease activity, resulting in a failure to synthesize its product, subunit IV of the cytochrome b (6)/f complex [11].

Analytical, diagnostic and therapeutic context of petD

• We created a Qo pocket mutant by site-directed mutagenesis of the chloroplast petD gene in Chlamydomonas reinhardtii [12].
• Here, we have used microarray analysis to assess changes in chloroplast, mitochondrial, and nuclear RNAs, and since few other RNAs were significantly altered in these mutants, conclude that Mcd1 is indeed specifically required for petD mRNA accumulation [8].

References