Polypeptide p41 of a Norwalk-Like Virus Is a Nucleic Acid-Independent Nucleoside Triphosphatase

Polypeptide p41 of a Norwalk-like virus is a nucleic acid-independent nucleoside triphosphatase.

Southampton virus (SHV) is a member of the Norwalk-like viruses (NLVs), one of four genera of the family Caliciviridae. The genome of SHV contains three open reading frames (ORFs). ORF 1 encodes a polyprotein that is autocatalytically processed into six proteins, one of which is p41. p41 shares sequence motifs with protein 2C of picornaviruses and superfamily 3 helicases. We have expressed p41 ...

The nucleic acid of African Horse-Sickness Virus

Kirchgesser and Dahlmann: Colorimetric assay of acid nucleoside triphosphatase

A photometric method for the determination of the acid nucleoside triphosphatase (EC 3.6.1.—) is described, in which inorganic phosphate is liberated from ATP or other nucleoside triphosphates. Colorimetric determination of liberated phosphate is based on the formation of a green complex of phosphomolybdate and malachite green hydrochloride. Optimal test conditions were evaluated as well as the...

Detection of norwalk-like virus in shellfish implicated in illness.

In the 1990s, Norwalk-like viruses (NLVs) were identified in patient specimens as the primary pathogen associated with shellfish-borne gastroenteritis in the United States. Identification of these viruses from implicated shellfish has been difficult due to inefficient recovery of viruses, natural polymerase chain reaction (PCR) inhibitors in shellfish, and low virus contamination. Recent improv...

The nucleoside triphosphatase and helicase activities of vaccinia virus NPH-II are essential for virus replication.

Vaccinia virus NPH-II is the prototypal RNA helicase of the DExH box protein family, which is defined by six shared sequence motifs. The contributions of conserved amino acids in motifs I (TGVGKTSQ), Ia (PRI), II (DExHE), and III (TAT) to enzyme activity were assessed by alanine scanning. NPH-II-Ala proteins were expressed in baculovirus-infected Sf9 cells, purified, and characterized with resp...