Mapping of the region of the tick‐borne encephalitis virus replicase adjacent to initiating substrate binding center

Abstract
Affinity labelling with aldehyde‐containing analogs of initiation substrates of nuclear fraction of tick‐borne encephalitis virus (TBEV) infected cells results in a labelling of a single polypeptide with a molecular mass of 68 kDa which was immunologically identified as TBEV NS3 protein. A single‐hit hydroxylamine hydrolysis, using limited and long‐term CNBr cleavages allowed one to identify Lys1800 and/or Lys1803 as the label attachment sites. These amino acid residues are situated in the proximity of the ‘B’‐site of NTP‐binding motif of viral RNA replicase.