Abstract: The invention relates to modified Dda helicases which can be used to control the movement of polynucleotides and are particularly useful for sequencing polynucleotides.

Abstract: Provided herein is a method of characterising a target polynucleotide as it moves with respect to a nanopore using a motor protein. Also provided are polynucleotide adapters and kits comprising such adapters. The methods, kits and adapters find use in characterising polynucleotides, for example in sequencing.

Abstract: A transmitter (20) having means (206, 207) to encode an input signal to form coded data, each element of said coded data having one of at least two discrete signal magnitude levels, the encoding means including in the coded data a periodic training sequence of data (T); and a receiver (30) to receive the coded data and, on the basis of the received training sequence, to adapt a threshold or thresholds to allow the discrete levels to be distinguishable from each other. The training sequence T may comprise a plurality of elements at least one of which, in turn, represents each one of the discrete signal levels. The receiver generates a look-up-table to store the adapted thresholds.