Avtor/Urednik | Dieckmann, T; Mitschang, L; Hofmann, M; Kos, J; Turk, V; Auerswald, EA; Jaenicke, R; Oschkinat, H | |
Naslov | The structures of native phosphorylated chicken cystatin and of a recombinant unphosphorylated variant in solution | |
Tip | članek | |
Vir | J Mol Biol | |
Vol. in št. | Letnik 234, št. 4 | |
Leto izdaje | 1993 | |
Obseg | str. 1048-59 | |
Jezik | eng | |
Abstrakt | The solution structures of the phosphorylated form of native chicken cystatin and the recombinant variant AEF-S1M-M29I-M89L were determined by 2D, 3D and 4D-NMR. The structures turn out to be very similar, despite the substitutions and the phosphorylation of the wild-type. Their dominant feature is a five-stranded beta-sheet, which is wrapped around a five-turn alpha-helix, as shown by X-ray crystallographic studies of wild-type chicken cystatin. However, the NMR analysis shows that the second helix observed in the crystal is not present in solution. The phosphorylation occurs at S80, which is located in a flexible region. For this reason, very few effects on the structure are observed. Comparison of structures of the unphosphorylated variant and the wild-type shows small effects on H84 which is located in the supposed recognition site of the serine kinase. This recognition site appears to be well structured as a large loop-containing bulge of the beta-sheet. The N termini of both mutants, which contribute to a large extent to the binding to the proteinase, are very flexible. A loop structure involving the residues L7 to A10 as found in related inhibitors, such as in the kininogen domains 2 and 3, is not sufficiently populated to be observed. | |
Deskriptorji | CYSTATINS PHOSPHOPROTEINS AMINO ACID SEQUENCE CHICKENS MODELS, MOLECULAR MOLECULAR SEQUENCE DATA NUCLEAR MAGNETIC RESONANCE PROTEIN STRUCTURE, SECONDARY RECOMBINANT PROTEINS SOLUTIONS ULTRACENTRIFUGATION |