title: Heat-labile enterotoxin crystal forms with variable A/B5 orientation. Analysis of conformational flexibility.
abstract: 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.
authors.affiliation: BIOSON Research Institute, University of Groningen, The Netherlands.
authors.forename: T K
authors.initials: TK
authors.lastname: Sixma
authors.forename: A
authors.initials: A
authors.lastname: Aguirre
authors.forename: A C
authors.initials: AC
authors.lastname: Terwisscha van Scheltinga
authors.forename: E S
authors.initials: ES
authors.lastname: Wartna
authors.forename: K H
authors.initials: KH
authors.lastname: Kalk
authors.forename: W G
authors.initials: WG
authors.lastname: Hol
mesh_terms: D001427:Bacterial Toxins / Q000737:chemistry*; D003460:Crystallization; D004768:Enterotoxins / Q000737:chemistry*; D004926:Escherichia coli / Q000737:chemistry*; D029968:Escherichia coli Proteins; D046911:Macromolecular Substances; D011487:Protein Conformation; D014961:X-Ray Diffraction
chemical_list: D001427:Bacterial Toxins; D004768:Enterotoxins; D029968:Escherichia coli Proteins; D046911:Macromolecular Substances; C027538:heat-labile enterotoxin, E coli