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41.
Using learning techniques previously described in this journal, we have built an expert system able to point to the start DNA point of a sequence and therefore to recognize a promoter. However, to build this system, we have focused on the TATA box and its environment. We have used this expert system to look for new promoters and also to construct new promoters. The results obtained are discussed. 相似文献
42.
Molecular cloning and nucleotide sequences of cDNAs specific for rat liver ribosomal proteins S17 and L30 总被引:10,自引:0,他引:10
O Nakanishi M Oyanagi Y Kuwano T Tanaka T Nakayama H Mitsui Y Nabeshima K Ogata 《Gene》1985,35(3):289-296
cDNA clones coding for rat liver ribosomal proteins S17 and L30 have been isolated by positive hybridization-translation assay from a cDNA library prepared from 8-9S poly(A)+RNA from free polysomes of regenerating rat liver. The cDNA clone specific for S17 protein (pRS17-2) has a 466-bp insert with the poly(A) tail. The complete amino acid (aa) sequence of S17 protein was deduced from the nucleotide sequence of the cDNA. S17 protein consists of 134 aa residues with an Mr of 15 377. The N-terminal aa sequence of S17 protein determined by automatic Edman degradation is consistent with the sequence data. The aa sequence of S17 shows strong homology (76.9%) to that of yeast ribosomal protein 51 [Teem and Rosbash, Proc. Natl. Acad. Sci. USA 80 (1983) 4403-4407] in the two-thirds N-terminal region. The cDNA clone specific for L30 protein (pRL30) has a 394-bp insert. The aa sequence of L30 protein was deduced from the nucleotide sequence of the cDNA. The protein consists of 114 aa residues with an Mr of 12 652. When compared with the N-terminal aa sequence of rat liver L30 protein [Wool, Annu. Rev. Biochem. 48 (1979) 719-754], pRL30 was found not to contain the initiation codon and 5'-noncoding region. The cDNA showed twelve silent changes in the coding region, one point mutation and one base deletion in the 3'-noncoding region, compared with mouse genomic DNA for L30 protein [Wiedemann and Perry, Mol. Cell Biol. 4 (1984) 2518-2528]. 相似文献
43.
44.
We have isolated adenovirus origins of DNA replication from both the right and left ends of the genome, which are functional on linear autonomously replicating mini-chromosomes. The mini-chromosomes contain two cloned inverted adenovirus termini and require non-defective adenovirus as a helper. Replicated molecules are covalently attached to protein, and DNA synthesis is initiated at the correct nucleotide even when the origins are not located at molecular ends. The activity of embedded origins leads to the generation of linear minichromosomes from circular or linear molecules. These observations therefore suggest that sequences within the adenovirus origin of replication position the protein priming event at the adenovirus terminus. Experiments investigating the regeneration of deleted viral inverted terminal repeat sequences show a sequence-independent requirement for inverted sequences in this process. This result strongly suggests that repair results from the formation of a panhandle structure by a displaced single strand. On the basis of these observations we propose a model for the generation of adenovirus mini-chromosomes from larger molecules. 相似文献
45.
Summary Eight transfer RNA (tRNA) genes which were previously mapped to five regions of the Pisum sativum (pea) chloroplast DNA (ctDNA) have been sequenced. They have been identified as tRNAVal(GAC), tRNAAsn(GUU), tRNAArg(ACG), tRNALeu(CAA), tRNATyr(GUA), tRNAGlu(UUC), tRNAHis(GUG), and tRNAArg(UCU) by their anticodons and by their similarity to other previously identified tRNA genes from the chloroplast DNAs of higher plants or from E. gracilis. In addition,two other tRNA genes, tRNAGly (UCC) and tRNAIle(GAU), have been partially sequenced. The tRNA genes are compared to other known chloroplast tRNA genes from higher plants and are found to be 90–100% homologous. In addition there are similarities in the overall arrangement of the individual genes between different plants. The 5 flanking regions and the internal sequences of tRNA genes have been studied for conserved regions and consensus sequences. Two unusual features have been found: there is an apparent intron in the D-loop of the tRNAGly(UCC), and the tRNAGlu(UUC) contains GATTC in its T-loop. 相似文献
46.
47.
Genes for human U4 small nuclear RNA 总被引:10,自引:0,他引:10
48.
B. Edwin Blaisdell 《Journal of molecular evolution》1983,19(2):122-133
Summary Coding sequences of eucaryotic nuclear DNA were characterized by an excess of short runs and a deficit of long runs of weak
and of strong hydrogen bonding bases; non-coding sequences by a deficit of short runs and an excess of long runs, in the same
of purines and of pyrimidines. The conservation of these attributes across DNA sequences coding for proteins of widely different
function, across widely different eucaryotic species for the same protein and across related genes that diverged a long time
ago and that now show large differences in base and, if coding, amino acid sequence suggested that these attributes have survival
value. It was concluded that these attributes constitute probalistic constraints on th primary structure (base sequence) of
both coding and non-coding DNA. 相似文献
49.
Joakim Galli Urban Lendahl Gabrielle Paulsson Christer Ericsson Tomas Bergman Mats Carlquist Lars Wieslander 《Journal of molecular evolution》1990,31(1):40-50
Summary We describe the structure of a gene expressed in the salivary gland cells of the dipteranChironomus tentans and show that it encodes 1 of the approximately 15 secretory proteins exported by the gland cells. This sp115,140 gene consists of approximately 65 copies of a 42-bp sequence in a central uninterrupted core block, surrounded by short nonrepetitive regions. The repeats within the gene are highly similar to each other, but divergent repeats are present in a pattern which suggests that the repeat structure has been remodeled during evolution. The 42-bp repeat in the gene is a simple variant of the more complex repeat unit present in the Balbiani ring genes, encoding four of the other secretory proteins. The structure of the sp115,140 gene suggests that related repeat structures have evolved from a common origin and resulted in the set of genes whose secretory proteins interact in the assembly of the secreted protein fibers. 相似文献
50.
Jacqueline Jollès Ellen M. Prager Emad S. Alnemri Pierre Jollès Ibrahim M. Ibrahimi Allan C. Wilson 《Journal of molecular evolution》1990,30(4):370-382
Summary Complete amino acid sequences are presented for lysozymesc from camel and goat stomachs and compared to sequences of other lysozymesc. Tree analysis suggests that the rate of amino acid replacement went up as soon as lysozyme was recruited for the stomach function in early ruminants. The two lysozymes from goat stomach are the products of a gene duplication that probably took place before the divergence of cow, goat, and deer about 25 million years ago. Partial sequences of three lysozymes from goat tears indicated that (a) the goat tear family of lysozymes may have diverged from the stomach lysozyme family by an ancient duplication and (b) later duplications are probably responsible for the multiple forms of tear and milk lysozymes in ruminants. 相似文献