the absence of this protein from the medium of cells infected with a spontaneous deletion mutant ( 6/2 ) suggested that the open reading frame ( orf ) was located within a 12,800-base pair segment near the left end of the genome ( g. kotwal and b. moss , nature ( london ) 335 , 176-178 , 1988 ) .
C0007634
cells
C0079941
open reading frame