Sixma T K, Aguirre A, Terwisscha van Scheltinga A C, Wartna E S, Kalk K H, Hol W G
BIOSON Research Institute, University of Groningen, The Netherlands.
FEBS Lett. 1992 Jun 29;305(2):81-5. doi: 10.1016/0014-5793(92)80869-i.
A new native crystal form of heat-labile enterotoxin (LT) has two AB5 complexes in the asymmetric unit with different orientations of the A subunit with respect to the B pentamer. Comparison with other crystal forms of LT shows that there is considerable conformational freedom for orientating the A subunit with respect to the B pentamer. The rotations of A in different crystal forms do not follow one specific axis, but most of them share a hinge point, close to the main interaction area between A and B5. Analysis of the two high-resolution structures available shows that these rotations cause very little change in the actual interactions between A and B5.
