Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:2.7.7.48 (transcriptase)
 9,479 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A sequence motif that is conserved in a number of S-adenosylmethionine (SAM)-utilizing methyltransferases and is implicated in SAM binding was identified in the N-terminal portion of NS5 proteins of flaviviruses and in lambda 2 protein of reovirus. An additional conserved motif was shared by these viral proteins and two distinct groups of methyltransferases including as the prototypes Rhodobacter capsulatus hydroxyneurosporene methylase (crtF gene product) and yeast 3,4-dihydroxy-5-hexaprenylbenzoate methylase (COQ3 gene product), respectively. Statistically significant similarity was revealed between the region of flavivirus NS5 containing the SAM-binding motif and a newly characterized family of putative methyltransferases from bacteria, yeast and plants, which is related to the Coq3 group. Amino acid sequence signatures were derived that are unique for NS5 proteins and different subsets of (putative) cellular methyltransferases. It is hypothesized that the N-terminal domain of NS5 is a methyltransferase involved in viral RNA capping. Thus NS5 may be a two-domain protein, with its C-terminal domain comprising the RNA-dependent RNA polymerase. The putative methyltransferase domain of flaviviruses is unrelated to the methyltransferase domain previously characterized in positive-strand RNA viruses of the alphavirus-like supergroup. The lack of sequence similarity and different location of the putative methyltransferase domain underscores the drastic difference in the genome layout of flaviviruses and alphaviruses. The identification of the putative methyltransferase domain in reovirus lambda 2 protein is compatible with the available evidence that this protein is the viral capping enzyme.
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PMID:Computer-assisted identification of a putative methyltransferase domain in NS5 protein of flaviviruses and lambda 2 protein of reovirus. 838 98

The nucleotide sequence of the large (L) genome segment of impatiens necrotic spot virus (INSV) has been determined, and herewith the complete nucleotide sequence of the whole, tripartite genome of this important tospovirus has been elucidated. The L RNA is 8776 nucleotides long and of negative polarity, containing one large ORF on the viral complementary strand. Comparison of the deduced amino acid sequence of the INSV L RNA primary translation product (330.3 kDa) with those of the L RNAs of other members of the family Bunyaviridae reveals that this protein represents the putative viral RNA-dependent RNA polymerase. A cluster dendrogram of the (putative) RNA polymerases indicates that the genera Tospovirus and Tenuivirus, though both encompassing ambisense plant-infecting viruses, have different affinities to the animal-infecting Bunyaviridae, tospoviruses being most closely related to the genus Bunyavirus, and tenuiviruses to the genus Phlebovirus.
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PMID:Completion of the impatiens necrotic spot virus genome sequence and genetic comparison of the L proteins within the family Bunyaviridae. 904 2