Eukaryotic RNAse H shares a conserved domain with caulimovirus proteins that facilitate translation of polycistronic RNA.
RNAse H (RNH1 protein) from the trypanosomatid Crithidia fasciculata has a functionally uncharacterized N-terminal domain dispensable for the RNAse H activity. Using computer methods for database search and multiple alignment, we show that the N-terminal domains of RNH1 and its homologue encoded by a cDNA from chicken lens are related to the conserved domain in caulimovirus ORF VI product that facilitates translation of polycistronic virus RNA in plant cells. We hypothesize that the N-terminal domain of eukaryotic RNAse H performs an as yet uncharacterized regulatory function, possibly in mRNA translation or turnover.
Mushegian
A R
AR
Department of Plant Pathology, University of Kentucky, Lexington 40546-0091.
Edskes
H K
HK
Koonin
E V
EV
D000595:Amino Acid Sequence; D000818:Animals; D017796:Caulimovirus / Q000737:chemistry*; D002645:Chickens; D017124:Conserved Sequence; D016831:Crithidia fasciculata / Q000201:enzymology*; D018076:DNA, Complementary; D005796:Genes; D008969:Molecular Sequence Data; D014176:Protein Biosynthesis; D012367:RNA, Viral / Q000235:genetics*; D016914:Ribonuclease H / Q000737:chemistry*; D016415:Sequence Alignment; D015534:Trans-Activators / Q000737:chemistry; D014764:Viral Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism
D018076:DNA, Complementary; D012367:RNA, Viral; D015534:Trans-Activators; D014764:Viral Proteins; D016914:Ribonuclease H