title: An alternate conformation of the hyperthermostable HU protein from Thermotoga maritima has unexpectedly high flexibility.
abstract: The homodimeric HU protein from the hyperthermophile Thermotoga maritima (HUTmar) is a model system which can yield insights into the molecular determinants of thermostability in proteins. Unusually for a thermostable protein, HUTmar exists in a structurally heterogeneous state as evidenced by the assignment of two distinct and approximately equally populated forms in solution. Relaxation measurements combined with chemical shift, hydrogen exchange, and nuclear Overhauser enhancement data confirm the main structural features of both forms. In addition, these data support a two-state model for HUTmar in which the major form closely resembles the X-ray structure while the very flexible minor form is less structured. HUTmar may therefore be a new example of the small class of hyperthermostable proteins with unexpected flexibility.
authors.affiliation: Bijvoet Center for Biomolecular Research, Universiteit Utrecht, Padualaan 8, 3584 CH Utrecht, The Netherlands.
authors.forename: Michael A
authors.initials: MA
authors.lastname: Durney
authors.forename: Rainer W
authors.initials: RW
authors.lastname: Wechselberger
authors.forename: Charalampos G
authors.initials: CG
authors.lastname: Kalodimos
authors.forename: Robert
authors.initials: R
authors.lastname: Kaptein
authors.forename: Constantinos E
authors.initials: CE
authors.lastname: Vorgias
authors.forename: Rolf
authors.initials: R
authors.lastname: Boelens
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry* / Q000235:genetics; D017124:Conserved Sequence; D018360:Crystallography, X-Ray; D019281:Dimerization; D004355:Drug Stability; D006358:Hot Temperature; D008969:Molecular Sequence Data; D019906:Nuclear Magnetic Resonance, Biomolecular; D018583:Pliability; D017354:Point Mutation; D011487:Protein Conformation; D017386:Sequence Homology, Amino Acid; D012996:Solutions; D020124:Thermotoga maritima / Q000737:chemistry* / Q000235:genetics
chemical_list: D001426:Bacterial Proteins; D012996:Solutions