Abstract:
The complex lifecycle of Myxococcus xanthus is facilitated by two types of motility, in
addition to several other pathways that regulate its lifecycle. The frz pathway modulates
the cellular reversal frequency and plays an important role in regulating both the
adventurous and social motilities of this bacteria. The foremost enzyme in this frz pathway
– FrzCD is a cytoplasmic chemoreceptor. Different post-translational modifications of
FrzCD correspond to different states of the receptor and can activate or repress the
signalling pathway resulting in modulation of the cellular reversal frequency. In this study,
we sought out to characterise one of the states – the unmethylated form of the receptor,
using a combination of biophysical approaches to decipher the oligomeric state of the
protein. Biochemical means to dissect the protein into its constituent N and C-terminal
domains to assign its structure and function, and subsequent biophysical characterisation
to assess the quality of the protein sample were carried out. During this process, we
discovered that the N-terminal domain of FrzCD binds to DNA, the first instance of a
methyl-acepting chemosensory protein (MCP) binding to DNA.
