Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.1.30.2 (endonuclease)
 18,621 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The enzymatic synthesis and characterization of (RP)-2',5'-AMPS trimer and tetramer (SP)-5'-O-(1-thiotriphosphates) from chirally substituted (SP)-[alpha-35S]ATP alpha S by 2',5'-oligoadenylate synthetase from interferon-treated L cell extracts are described. The (RP)-ATP alpha S isomer is not a substrate for the synthetase. The identification of the trimer and tetramer analogues (molar ratio 70:30) was accomplished by high-performance liquid chromatography and subsequent separation by charge using DEAE-cellulose thin-layer chromatography. The digestion of the analogue by snake venom phosphodiesterase I (SVPD) to [alpha-35S]ATP alpha S and [35S]AMPS but not by T2 RNase demonstrated the presence of the 2',5' linkage. The assignment of RP configuration of the 2',5'-phosphorothiodiester linkage was based on the highly specific stereoselectivity of SVPD for RP diastereomers [Burgers, P. M. J., & Eckstein, F. (1978) Proc. Natl. Acad. Sci. U.S.A. 75, 4978-4800; Bryant, F. R., & Benkovic, S. J. (1979) Biochemistry 18, 2825-2828; Nelson, P. S., Bach, C. T., & Verheyden, J. P. H. (1984) J. Org. Chem. 49, 2314-2317]. This suggests that the synthesis of the phosphorothioate analogues proceeded via inversion of configuration at the chiral phosphorus of (SP)-ATP alpha S. The putative (RP)-2',5'-AMPS tetramer (SP)-5'-O-(1-thiotriphosphate) displaced the 2',5'-p3A4[32P]pCp analogue from 2',5'-oligoadenylate-dependent endonuclease 5 times more efficiently than did equimolar concentrations of authentic 2',5'-adenylate tetramer triphosphate. Furthermore, in studies using the calcium phosphate coprecipitation technique, the 2',5'-phosphorothioate trimer and tetramer analogues inhibited protein synthesis better than did 2',5'-adenylate trimer and tetramer triphosphates.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:2',5'-Oligoadenylates chiral at phosphorus: enzymatic synthesis, properties, and biological activities of 2',5'-phosphorothioate trimer and tetramer analogues synthesized from (SP)-ATP alpha S. 399 75

The need for comparative studies of iridoviruses to elucidate the relationships between them has been well appreciated. Sixteen iridoviruses, including type species from each of the four recognized genera of the Iridoviridae, were compared by restriction endonuclease characterization, hybridization to the major structural protein (MSP) gene of an invertebrate iridescent virus (IV) isolate at various stringencies, PCR amplification of the MSP gene region and by dot-blot hybridization studies. The results broadly supported previous serological studies. The vertebrate iridoviruses, frog virus 3 (genus Ranavirus) and flounder lymphocystivirus (genus Lymphocystivirus), appeared distinct from one another and from the invertebrate isolates. Naming and numbering invertebrate IV isolates according to history and host is no longer useful since IVs infect a number of species. A revised system, involving names based on the geographical origin of the isolate is proposed, in line with other virus families. The large IVs of invertebrates represented by Vero Beach IV (previously IV3 or mosquito IV; genus Chloriridovirus) showed little similarity to any other IVs. Members of the genus Iridovirus, the small invertebrate IVs, fell into three distinct groups of interrelated isolates. The largest group, containing the Plowden (IV1), Tia (IV2), Nelson (IV9, IV10 and IV18), Aberystwyth (IV22), Srinagar (IV24), Fort Collins (IV29) and Stoneville (IV30) iridoviruses, is named the Polyiridovirus complex. The Plowden iridovirus (IV1) is suggested as type species for this complex given the data available on its molecular biology. Based on previously published data, Timaru (IV16 and IV19) and Uitenhage (IV23) iridoviruses are also assigned to this complex. The second but smaller group is named the Oligoiridovirus complex, which includes Dazaifu (IV6) as the type species and contains Ntondwe (IV21 and IV28) on a tentative basis. Riverside IV (IV31) was distinct from both of the other groups, and is proposed as a third complex, Crustaceoiridovirus.
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PMID:Proposals for a new classification of iridescent viruses. 820 95