Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.1.26.9 (ribonuclease)
 6,589 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The amino acid sequences of the pancreatic ribonucleases from African porcupine (Hystrix cristata) and casiragua (Proechimys guairae, a caviomorph rodent species related to the coypu) were determined. The ribonucleases were isolated form minces of pancreatic tissue which had been used for the extraction of the insulins. The results of the sequence determinations of residues 67-78 in both enzymes were ambiguous. Therefore, homology with other ribonucleases has been used in deriving these sequences. At position 94 aspartic acid was found, while all other ribonuclease sequenced to date have asparagine at this position. This may indicate a specific deamidation as a result of the acidic conditions during the extraction of insulin. The amino acid sequence of African porcupine ribonuclease shows a close relationship with those of the South-American caviomorph rodents, which implies that the hystricomorph suborder of the rodents, to which both the African porcupine and the caviomorphs belong, is a natural (evolutionary) taxon. Both porcupine and casiragua ribonuclease are glycoproteins with complex-type carbohydrate chains attached to asparagine-34.
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PMID:The primary structures of pancreatic ribonucleases from African porcupine and casiragua, two hystricomorph rodent species. 711 27

There have been many studies on the chemistry of mammalian pancreatic ribonucleases (ribonucleases 1), but the functional biology of this family of homologous proteins is still largely unknown. Many studies have been performed on the molecular evolution and properties of this enzyme from species belonging to a large number of mammalian taxa, including paralogous gene products resulting from recent gene duplications. Novel ribonuclease 1 sequences were determined for three rodent species (gundi, brush-tailed porcupine, and squirrel), rabbit, a fruit bat, elephant, and aardvark, and the new sequences were used for deriving most parsimonious networks of ribonucleases from different mammalian orders, including earlier determined nucleotide sequences and also a larger set of protein sequences. Weak support for interordinal relationships were obtained, except for an Afrotheria clade containing elephant and aardvark. Results of current analyses and also those obtained 20 years ago on amino acid sequences confirm conclusions derived recently from larger data sets of other molecules. Several examples of recent gene duplications in ribonucleases 1 are discussed, with respect to illustrate the concepts of orthology and paralogy. Previously evidence was presented for extensive parallelism between sequence regions with attached carbohydrate (about one quarter of the molecule) of unrelated species with cecal digestion (pig and guinea pig). These features are also present in the sequences of elephant and fruit bat, species with cecal digestion, but with a very low ribonuclease content in their pancreas.
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PMID:Molecular evolution of mammalian ribonucleases 1. 1274 50