Molecular cloning and nucleotide sequence of cDNA specific for rat ribosomal protein L5

Abstract

cDNA clones specific for rat ribosomal protein L5, which is the protein moiety of 5s RNA protein particles, were isolated by using a mixture of tetradecamer deoxyribonucleotide probes reflecting the amino acid sequence of the N-terminal portion of L5. A cDNA clone (pRL5-1) lacking the 3'-terminal region of L5 was isolated by hybrid-selected translation and shown to be L5-specific by the identity of the deduced amino acid sequence and that of the N-terminus of protein L5. pRL5-1 was then used to select another clone @RL5-2) by colony hybridization which contained the entire coding region, 3'-non-coding region and poly(A) addition signal. The nucleotide sequence of L5-specific cDNA was determined by using these two clones. It contained a total of 1069 base pairs: 123 base pairs in the 5'-non-coding region, 894 base pairs in the coding region and 52 base pairs in the 3'-non-coding region. The poly(A) addition signal appeared at the 33rd nucleotide after the termination codon. The amino acid sequence deduced from this nucleotide sequence consists of 296 amino acids. The homology of amino acid sequence between L5 and other 5s RNA-binding proteins is discussed.The large ribosomal subunits of both procaryotes and eucaryotes contain 5s RNA, which can be released in the form of a complex with one or more ribosomal proteins by various treatments (for review, see [l]). A 5s RNA-protein complex is, for example, released from rat liver 60s subunits by EDTA treatment [2] or other methods 13 -51, and we have identified its protein moiety as protein L5 [6] according to the proposed uniform nomenclature [7]. The existence of the 5S-RNA-L5-protein complex in the 60s ribosomal subunits is shown by cross-linking of 5 s RNA to L5 by ultraviolet irradiation of this particle [8] or by treating it with sodium periodate followed by reduction by sodium borohydride [9]. We have also shown [lo] that ribosomal protein L5 is crosslinked to mRNA besides proteins S3a, S6 and L6 by ultraviolet irradiation of the total polysomal fraction of rat liver and to proteins S4 and S25 by treatment of rat liver 80s ribosomes with 2-iminothiolane [ll]. These results suggest that the 5S-RNA-L5 complex is located at the boundary between the large and the small subunits and interacts with mRNA.Others have reported that L5 is located at the peptidyl (P) site in the 80s initiation complex [12].The interaction between 5s RNA and protein L5 has been extensively studied and the L5 binding site in 5s RNA has been identified by Aoyama et al. [13] and Huber and Wool [14]. From the limited homology of the partial amino acid sequences of fragments CN1 and CN2, cleaved products of yeast 5s RNA binding protein (YL13), with those of Escherichia coli 5s RNA binding proteins (EL18, EL5 and EL25), Nazar et al. [15] and Yaguchi et al. [16] proposed that the single large eucaryotic 5s RNA binding protein may have evolved through a fusion of genes for the multiple 5s RNA binding proteins in procaryotes.To elucidate further the function, the mode of interaction with 5s RNA and...

Interaction of the HIV-1 Rev cofactor eukaryotic initiation factor 5A with ribosomal protein L5

“…The amino acid sequence deduced (Fig. 1B) is identical with the recently published human sequence and is closely related to the rat homologue found in the GenBank database (43,47).…”

Translational Control of Ribosomal Protein Production in Mammalian Cells

“…More over, the 5'UTRs of rp mRNAs are generally relatively short (25-50 nucleotides) and only one (L5) has been found to contain an AUG upstream of the true initiator codon [22], One common feature noted in all se quenced vertebrate rp mRNAs is an oligopy rimidine tract at the 5' terminus. In cases for which complete sequence information is available, this element is found to consist of a C residue at the cap site followed by an uninterrupted sequence of 7-13 pyrimidines (table 2).…”

Nucleotide sequence of cloned cDNA specific for rat ribosomal protein L27

“…During the cloning of probes to study the regulation of expression of ribosomal protein genes, we realized that analyses of cDNAs are a more efficient way to investigate the structure of ribosomal proteins. Thus, we determined the structures of rat ribosomal proteins S11 [8], S17 [9], S26 [lo], L5 [11], L30 [9], L31 [12] and L35a [13]. Chan et al and Lin et al also determined the structure of rat ribosomal protein S12 [14], L5 [15], L7 [16] and L19 [17] in the same way.…”