Protein Domain : Luteovirus Orf2 putative replicase 1 IPR018019

Type	Family
Description	ORF2 of Potato leafroll virus (PLrV) encodes a polyprotein which is translated following a -1 frameshift. The polyprotein has a putative linear arrangement of membrane achor-VPg-peptidase-polmerase domains. The serine peptidase domain which is found in this group of sequences belongs to MEROPS peptidase family S39 (clan PA(S)), subfamily S39B. It is likely that the peptidase domain is involved in the cleavage of the polyprotein [ ].The nucleotide sequence for the RNA of PLrV has been determined [ , ]. The sequence contains six large open reading frames (ORFs). The 5' coding region encodes two polypeptides of 28K and 70K, which overlap in different reading frames; it is suggested that the third ORF in the 5' block is translated by frameshift readthrough near the end of the 70K protein, yielding a 118K polypeptide []. Segments of the predicted amino acid sequences of these ORFs resemble those of known viral RNA polymerases, ATP-binding proteins and viral genome-linked proteins. The nucleotide sequence of the genomic RNA of Beet western yellows virus (BWYV) has been determined []. The sequence contains six long ORFs. A cluster of three of these ORFs, including the coat protein cistron, display extensive amino acid sequence similarity to corresponding ORFs of a second luteovirus: Barley yellow dwarf virus [].
Short Name	Luteovirus_Orf2