The matrix protein of vesicular stomatitis virus inhibits nucleocytoplasmic transport when it is in the nucleus and associated with nuclear pore complexes.

The matrix (M) protein of vesicular stomatitis virus (VSV) is a potent inhibitor of bidirectional nuclear transport. Here we demonstrate that inhibition occurs when M protein is in the nucleus of Xenopus laevis oocytes and that M activity is readily reversed by a monoclonal antibody (alphaM). We identify a region of M protein, amino acids 51 to 59, that is required both for inhibition of transport and for efficient recognition by alphaM.

Comparison of the 5' nuclease activities of taq DNA polymerase and its isolated nuclease domain.

Many eubacterial DNA polymerases are bifunctional molecules having both polymerization (P) and 5' nuclease (N) activities, which are contained in separable domains. We previously showed that the DNA polymerase I of Thermus aquaticus (TaqNP) endonucleolytically cleaves DNA substrates, releasing unpaired 5' arms of bifurcated duplexes. Here, we compare the substrate specificities of TaqNP and the isolated 5' nuclease domain of this enzyme, TaqN.