Nucleic Acids Research, Vol. 20, No. 20 5473
Q--DI 1992 Oxford University Press
Structure of a gene in the dipteran Chironomus tentans encoding a yeast ribosomal YL10 protein homologue J.Galli and L.Wieslander* Department of Cell and Molecular Biology, Medical Nobel Institute, Karolinska Institutet, S-104 01 Stockholm, Sweden EMBL accession no. X68332
Submitted September 21, 1992 Although the ribosomal RNAs appear capable of enzymatic function on their own (1), knowledge about the proteins of the small and large ribosomal subunits will be required for a complete structural and functional understanding of the ribosome. Here we report the structure, the chromosomal location and the expression pattern of a gene in the dipteran species Chironomus tentans which, based on the degree of identity encodes a protein corresponding to the Saccharomyces cerevisiae YL1O ribosomal protein (2). Previously, the amino terminal region of the yeast protein and part of an apparent human homologue has been reported (3), but not the entire coding region nor the gene structure. The C. tentans gene product is 65% identical to the yeast protein in a 43 amino acid overlap and 71% identical to the human gene product in a 128 amino acid overlap (Figure 1). The DNA was cloned from a C. tentans salivary gland cDNA library during screening for abundant salivary gland mRNAs; the corresponding 0.9 kb mRNA is as abundant as the tissue specifically expressed secretory gland protein mRNAs. The mRNA is abundant also in all other tissues tested as well as in a C.tentans embryonic epithelial cell line. The encoded protein has 204 amino acid residues. The calculated molecular weight is 24213 and the isoelectric point is 11.9. Starting at residue 163, an ATP/GTP-binding site motif is present (4). A comparison between the mRNA and the gene, isolated from a genomic library, revealed that the gene contains three introns. Two of the introns are in the 5' untranslated region, between position 31 and 32 and position 50 and 51. The third intron is in codon number 104, between codon position 1 and 2. The transcription start site, as defined by cDNA primer extension, was shown to be 76 bp upstream of the AUG codon. The chromosomal location of the gene was determined by in situ hybridisation and found to be in region 4-5 on chromosome H in the C.tentans genome.
*
To whom
correspondence should be addressed
ACKNOWLEDGEMENTS We thank Kerstin Bernholm for technical assistance. This work was supported by the Swedish Natural Science Foundation, Magnus Bergvalls Stiftelse, Ragnar and Torsten S6derbergs Stiftelser and Karolinska Institutet.
REFERENCES 1. Noller,H.F., Hoffarth,V. and Zimniak,L. (1992) Science 256, 1416-1419. 2. Otaka,E., Higo,K. and Osawa,S. (1982) Biochemistry 21, 4545-4550. 3. Adams,M., Dubnick,M., Kerlavage,R., Moreno,R., Kelley,J.,M., Utterback,T.,R., Nagle,J.,W., Fields,C. and Venter,J.C. (1992) Nature 355, 632-634. 4. Saraste,M., Sibbald,P.R. and Wittinghofer,A. (1990) Trends Biochem. Sci. 15, 430-434.
50
c
a
y
EYX1
C
XKSDVR
c
|LGYKAKQ*
C B
VAEE
C
WVCNAVHKHRELRGLTSAGKSSRGVGKGYRYSQTIGGSRRAAWRRXNRLHLRRYR
a
V
YRIRVRRG
LNSYW.VA SPEFLLGFG
G
T
RR
100
YEVICVDPFHNAVRRDPKVN
149
F
204
Figure 1. Comparison between the complete C.tentans (C) and partial human (H) and Saccharomyces cerevisiae (Y) protein sequences. Boxed amino acids are identical in all three species. The C.tentans and human sequences are derived from the nucleotide sequences.
Q--DI 1992 Oxford University Press
Structure of a gene in the dipteran Chironomus tentans encoding a yeast ribosomal YL10 protein homologue J.Galli and L.Wieslander* Department of Cell and Molecular Biology, Medical Nobel Institute, Karolinska Institutet, S-104 01 Stockholm, Sweden EMBL accession no. X68332
Submitted September 21, 1992 Although the ribosomal RNAs appear capable of enzymatic function on their own (1), knowledge about the proteins of the small and large ribosomal subunits will be required for a complete structural and functional understanding of the ribosome. Here we report the structure, the chromosomal location and the expression pattern of a gene in the dipteran species Chironomus tentans which, based on the degree of identity encodes a protein corresponding to the Saccharomyces cerevisiae YL1O ribosomal protein (2). Previously, the amino terminal region of the yeast protein and part of an apparent human homologue has been reported (3), but not the entire coding region nor the gene structure. The C. tentans gene product is 65% identical to the yeast protein in a 43 amino acid overlap and 71% identical to the human gene product in a 128 amino acid overlap (Figure 1). The DNA was cloned from a C. tentans salivary gland cDNA library during screening for abundant salivary gland mRNAs; the corresponding 0.9 kb mRNA is as abundant as the tissue specifically expressed secretory gland protein mRNAs. The mRNA is abundant also in all other tissues tested as well as in a C.tentans embryonic epithelial cell line. The encoded protein has 204 amino acid residues. The calculated molecular weight is 24213 and the isoelectric point is 11.9. Starting at residue 163, an ATP/GTP-binding site motif is present (4). A comparison between the mRNA and the gene, isolated from a genomic library, revealed that the gene contains three introns. Two of the introns are in the 5' untranslated region, between position 31 and 32 and position 50 and 51. The third intron is in codon number 104, between codon position 1 and 2. The transcription start site, as defined by cDNA primer extension, was shown to be 76 bp upstream of the AUG codon. The chromosomal location of the gene was determined by in situ hybridisation and found to be in region 4-5 on chromosome H in the C.tentans genome.
*
To whom
correspondence should be addressed
ACKNOWLEDGEMENTS We thank Kerstin Bernholm for technical assistance. This work was supported by the Swedish Natural Science Foundation, Magnus Bergvalls Stiftelse, Ragnar and Torsten S6derbergs Stiftelser and Karolinska Institutet.
REFERENCES 1. Noller,H.F., Hoffarth,V. and Zimniak,L. (1992) Science 256, 1416-1419. 2. Otaka,E., Higo,K. and Osawa,S. (1982) Biochemistry 21, 4545-4550. 3. Adams,M., Dubnick,M., Kerlavage,R., Moreno,R., Kelley,J.,M., Utterback,T.,R., Nagle,J.,W., Fields,C. and Venter,J.C. (1992) Nature 355, 632-634. 4. Saraste,M., Sibbald,P.R. and Wittinghofer,A. (1990) Trends Biochem. Sci. 15, 430-434.
50
c
a
y
EYX1
C
XKSDVR
c
|LGYKAKQ*
C B
VAEE
C
WVCNAVHKHRELRGLTSAGKSSRGVGKGYRYSQTIGGSRRAAWRRXNRLHLRRYR
a
V
YRIRVRRG
LNSYW.VA SPEFLLGFG
G
T
RR
100
YEVICVDPFHNAVRRDPKVN
149
F
204
Figure 1. Comparison between the complete C.tentans (C) and partial human (H) and Saccharomyces cerevisiae (Y) protein sequences. Boxed amino acids are identical in all three species. The C.tentans and human sequences are derived from the nucleotide sequences.
