Send to

Choose Destination
Open Virol J. 2011;5:103-8. doi: 10.2174/1874357901105010103. Epub 2011 Sep 6.

The insertion of fluorescent proteins in a variable region of respiratory syncytial virus L polymerase results in fluorescent and functional enzymes but with reduced activities.

Author information

INRA, Unité de Virologie Immunologie Moléculaires UR892, F-78350 Jouy-en-Josas, France.


The respiratory syncytial virus (RSV) Large protein L is the catalytic subunit of the RNA-dependent RNA polymerase complex. Currently, no structural information is available for RSV L. Sequence alignments of L protein from human and bovine strains of RSV revealed the existence of two variable regions, VR1 and VR2. Following comparison with morbillivirus and rhabdovirus L genes, VR2, which is located between domains V and VI, was chosen as an insertion site for sequences encoding the epitope tag HA or the fluorescent proteins eGFP and mCherry. Recombinant tagged-L proteins co-localized with RSV N and P proteins in transfected cells. These recombinant polymerases were shown to be functional using a viral minigenome system assay, their activities being reduced by ~70% compared to the unmodified L polymerase. We have also shown by site-directed mutagenesis that the GDNQ motif (residues 810-813 for the Long strain of HRSV) is essential for L activity.


HA tag; L protein; RNA-dependent RNA polymerase; Respiratory syncytial virus; eGFP; mCherry.

Supplemental Content

Full text links

Icon for PubMed Central
Loading ...
Support Center