Chloroplast ribosomal protein L13 is encoded in the nucleus and is considerably larger than its bacterial homologue. Construction, immunoisolation, and nucleotide sequence (including transit peptide) of its cDNA clone from an angiosperm

• Published in: The Journal of biological chemistry Vol. 264; no. 4; pp. 1968 - 1971
• Main Authors: Phua, S.H, Srinivasa, B.R, Subramanian, A.R
• Format: Journal Article
• Language: English
• Published: Bethesda, MD American Society for Biochemistry and Molecular Biology 05-02-1989
• Subjects: ADN; Amino Acid Sequence; ANGIOSPERMAS; ANGIOSPERME; ANGIOSPERMS; Base Sequence; Biological and medical sciences; Biotechnology; Cell Nucleus - metabolism; Chloroplasts - metabolism; CLONE; CLONES; DNA; Escherichia coli - genetics; Fundamental and applied biological sciences. Psychology; Genes; Genes. Genome; Genetic engineering; Genetic technics; Methods. Procedures. Technologies; Molecular and cellular biology; Molecular cloning; Molecular genetics; Molecular Sequence Data; NOYAU CELLULAIRE; NUCLEO; NUCLEOTIDE; NUCLEOTIDES; NUCLEOTIDOS; NUCLEUS; PLANT PROTEINS; Plants - genetics; PLASTE; PLASTIDIOS; PLASTIDS; PROTEINAS VEGETALES; PROTEINE VEGETALE; Restriction Mapping; Ribosomal Proteins - genetics; RIBOSOMAS; RIBOSOME; RIBOSOMES; Sequence Homology, Nucleic Acid; Nucleotide sequence; Gene library; Spinacia oleracea; Ribosomal protein; Chenopodiaceae; Screening; Complementary DNA; Dicotyledones; Angiospermae; Restriction map; Spermatophyta; Molecular cloning; Chloroplast
• ISSN: 0021-9258; 1083-351X

Chloroplast ribosomes of higher plants are of the prokaryotic ribosome motif but, unlike in bacteria, their ribosomal protein
(r-protein) genes are distributed between the organelle and the nucleus. In order to isolate some of the nuclear-encoded r-protein
genes, we have raised antibodies to several spinach chloroplast r-proteins and constructed spinach cDNA expression libraries
in lambdagt11. Screening the libraries with one of the antisera yielded three cDNA clones for r-protein L13, an early 50 S
subunit assembly protein essential for RI50 formation. The cDNA clone encodes, beginning with a Met codon in the consensus
plant initiator context, a polypeptide of 250 amino acid residues. The NH2-terminal 60 residues bear the characteristic features
of a chloroplast transit peptide. The putative mature L13 protein, which has common immunoepitopes with Escherichia coli L13,
is 34% longer than the E. coli homologue. It has 56% sequence identity with E. coli L13 in the homologous region, but no identity
to any known protein in the extra stretch. There are two neighboring ATG codons in the 5' region and two putative plant polyadenylation
signals in the 3'-untranslated region of the cDNA. Their possible effect to increase translational efficiency is discussed,
and the importance of encoding a RI50 protein in the nuclear genome for possible nuclear control of chloroplast protein synthesis
is noted.