Structural and biochemical basis for the difference in the helicase activity of two different constructs of SARS-CoV helicase

The non—structural protein 13 (nsp13) of Severe Acute Respiratory Syndrome Coronavirus (SARS—CoV) is a helicase that separates double—stranded RNA or DNA with a 5'—3' polarity, using the energy of nucleotide hydrolysis. We have previously determined the minimal mechanism of helicase function by nsp13 where we demonstrated that the enzyme unwinds nucleic acid in discrete steps of 9.3 base—pairs each with a catalytic rate of 30 steps per second. In that study we used different constructs of nsp13 (GST and H6 constructs). GST—nsp13 showed much more efficient nucleic acid unwinding than the H6—tagged counterpart. At 0.1 second, more than 50% of the ATP is hydrolyzed by GST—nsp13 compared to less than 5% ATP hydrolysis by H6—nsp13. Interestingly, the two constructs have the same binding affinity for nucleic acids. We, therefore propose that the difference in the catalytic efficiency of these two constructs is due to the interference of ATP binding by the histidine tag at the amino—terminus of nsp13.

Medienart:

E-Artikel

Erscheinungsjahr:

2012

Erschienen:

2012

Enthalten in:

Zur Gesamtaufnahme - volume:58

Enthalten in:

Cellular and molecular biology (Noisy-le-Grand, France) - 58(2012), 1 vom: 22. Dez., Seite 114-21

Sprache:

Englisch

Beteiligte Personen:

Adedeji, A O [VerfasserIn]
Singh, K [VerfasserIn]
Sarafianos, S G [VerfasserIn]

Themen:

8L70Q75FXE
Adenosine Triphosphate
DNA Helicases
EC 3.6.4.-
Journal Article
Nucleic Acids
Research Support, N.I.H., Extramural
Research Support, Non-U.S. Gov't

Anmerkungen:

Date Completed 04.06.2013

Date Revised 07.12.2022

published: Electronic

Citation Status MEDLINE

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM22375837X