id	author	title	date	pages	extension	mime	words	sentences	flesch	summary	cache	txt
cord-344410-yo9libo0	Zhou, Yan	Mutational analysis of the SDD sequence motif of a PRRSV RNA-dependent RNA polymerase	2011-09-16		.txt	text/plain	5856	295	57	A core palm structure containing the four motifs (A-D) found in all classes of polymerases [1] is present in the C-terminal region of nsp9; therefore, it is possible to identify RdRp catalytic activity by testing whether the conserved SDD motif (at residues 3050 to 3052 of nsp9) itself is essential for virus replication (Figure 1) . To study the impact of mutations in the SDD motif on PRRSV transcription, RT-PCR analysis of the sg mRNA7s was performed on the total RNAs obtained from mock-transfected BHK-21 cells and cells transfected with pMDD, pSAD, pSED, pSND, pSGD, pSDA, pSDE, pSDN, pSGA, pGND, pGDD, and pAPRRS, using a forward primer located in the leader region and a reverse primer in ORF7. The mutant PRRSV full-length cDNA clones pMDD, pSAD, pSED, pSND, pSGD, pSDA, pSDE, pSDN, pGDN, and pSGA carrying mutations specifying the SDD motif in the viral replicase (Table 1) , were transfected into BHK-21 cells and failed to produce sg mRNA7s (Figure 2) .	./cache/cord-344410-yo9libo0.txt	./txt/cord-344410-yo9libo0.txt