Molecular Biology Of R-Phycoerythrin Of Corallina Officinalis

We report the nucleotide sequence of the PE alpha and beta subunit encoding genes from Corallina officinalis. The sequence was isolated using a PCR primer designed based on the conserved PE gene sequences .The beta subunit encoding gene (rpeB) contained an open reading frame of 534 bp, while the a subunit (rpeA) was 495 bp (GenBank accession number: AF510986). The intergenic sequence contain 101 nucleotide.Through RACE(Rapid amplification of cDNA ends),we get cDNA sequence encoding a and beta subunit of phycoerythrin ,which contain 2257bp,consisting of 493 nucleotide that locate in the upstream of the initiation codon of beta subunit, 534 coding for beta subunit(coding 177 amino acid), 101 nucleotide for intergenic region , 495 nucleotide that draw near the 5' terminal of a subunit(coding 164 amino acid)and634 nucleotide locating in the down stream of the terminal codon of a subunit, including poly(A) of 30bp. Scanning the GenBank database , cDNA sequence encoding a and P subunit was not presented. The cDNA sequence encoding alpha and beta subunit of phycoerythrin was first reported,which indeed prove the cotranscription of rpeB and rpeA.In addition, we determined the N- terminal amino acid sequence (P83592) of Y subunit and can't find the similar sequence in known protein. Degenerate primers were designed based on the N-terminal partial sequence from purified PE of Corallina officinalis to amplify the corresponding cDNA by rapid amplification of cDNA ends(RACE). The cloning and sequencing of a full length cDNA of the gamma subunit of R-PE is obtained.The cDNA contains an open reading frame for a peptide of 320 amino acids .A 5' UTR (untranslated region) of 1203 bp was found upstream from the translation initiation site. A 3' UTR of 145 bp were located downstream the terminal codon,including poly(A) of 26bp.cDNA of the Y subunit and its deduced amino acid sequence is consistent with the N-terminal partial sequence from purified PE of Corallina officinalis. In addition,we get the DNA sequence of gamma subunit,which indicate no intron in the open reading frame.Moreover, We comparatively analyze sequence structure, characteristic, function and similarities in the nucleotide and in amino acid level with several biological softwares.