Previous studies of norovirus polyprotein processing have yielded three major products following in vitro transcription and translation, representing the uncleaved 3ABCD, N-term and 2C proteins. However, initial analysis of JV polyprotein processing indicated that only two major proteins are synthesised initially which, based on molecular weight predictions, are the 3ABCD (110 kDa) and the 2C (39 kDa). The lack of an N-terminal protein encoded by the JV 59GS, predicted to be 35.3 kDa, is unique among the noroviruses that have been studied in this way. The in vitro transcription and translation profile for JV was therefore studied in more detail. As initial experiments had analysed TNTH reactions following a 1 hr incubation, reaction aliquots were harvested at time points before and after the recommended 1 hr incubation.