Primary Structure of Cytochrome b₅ from Cauliflower (Brassica oleracea L.) Deduced from Peptide and cDNA Sequences

Abstract

ABSTRACT

Generation of Expressed Sequence Tags of Random Root cDNA Clones of Brassica napus by Single-Run Partial Sequencing

“…The PIR search showed that the clone has 54% amino acid identity with the rat Cyt i> 5 gene, and the GenBank search showed that the clone has 54% nucleotide sequence identity with the chicken probing with the chicken gene. The first plant Cyt b5 gene was isolated from cauliflower soon after our data base search (Kearns et al, 1992), and the R216 clone showed 62% amino acid identity with the cauliflower Cyt b5 sequences, suggesting that the R216 clone is likely to encode a Cyt b5 in B. napus. The cauliflower clone was isolated by purifying the Cyt bs protein from floret microsomes, obtaining partial peptide sequences of the protein, and then performing polymerase chain reaction of the cauliflower cDNA with the oligonucleotides that correspond to the peptide sequence.…”

Tobacco cytochromeb 5: cDNA isolation, expression analysis andin vitro protein targeting

“…This domain has been demonstrated to be responsible for the targeting of rat cytochrome b5 to the ER membrane [ 17]. Moreover, the tobacco sequence did not contain the putative ER retention C-terminal motif (KKX) reported in the cauliflower cytochrome b 5 sequence [11 ]. No hydrophobic N-terminal signal sequence was apparent from the hydropathy plots.…”

“…Primers were selected by comparison of mammalian and plant sequences. In the latter case this was protein sequences determined from cauliflower and safflower ( [11], M . A .…”

“…The deduced amino acid sequence of 139 residues showed 82 % identity to the deduced amino acid sequence of the cauliflower protein, the only other published example of a plant cytochrome b5 [ 11 ], and high homology to animal microsomal cytochrome b5 sequences ( Fig. 2A).…”

“…The role of cytochrome b5 in plants is less well understood although it is known to be involved in the desaturation of acylcomplex lipids in oilseeds [10,31] and in the A12 hydroxylation of oleate in castor bean (Ricinus communis) [32]. The amino acid sequence of cytochrome b5 has been determined for a variety of animal species (see [23]) and for a single plant species [ 11 ]. The protein is highly conserved and is composed of two functional domains, a hydrophilic amino terminal domain of ca.…”