Fig. 2: Building the 4-mer map.
Conductance curve consensuses for four of the 16 strands used in training the 4mer model for variable-voltage sequencing of ALIEN DNA. Consensus curves are constructed by hand aligning PZBS 4-mers to the variable voltage conductance curves ensuring consistency across strands, i.e., conductance curves for the 4-mer “PZZZ” should be similar each place it occurs in the training data. Because Hel308 helicase moves DNA through the nanopore in two ~half-nucleotide steps per ATP hydrolysed, each 4-mer is assigned two conductance curves. We have determined previously that these steps correspond to conformational changes of the helicase. Integer nucleotide steps correspond to Hel308 helicase in the open conformation while half-integer steps correspond to the two walker domains in the closed conformation. Sequences displayed are in time-order so appear 3′ to 5′ because Hel308 helicase walks from 3′ to 5′. Consensuses are constructed from 20, 24, 30, and 27 reads, respectively.
