crystal structure, as part of four intact repressor molecules bound to two adjacent operator
sites. The structure of region 136–230 in 1gfx was found to be nearly identical to the
independently determined crystal structure of the 132–236 fragment, 1f39, released later by
the PDB. Later, two more tetrameric models of the λ repressor tetramer bound to two
adjacent operator sites were constructed by us; in one of these, 1j5g, the N-domain and C …