Oligomerization, membrane anchoring, and cellulose-binding characteristics of AbpS, a receptor-like Streptomyces protein
Autor(en): | Walter, S Schrempf, H |
Stichwörter: | Biochemistry & Molecular Biology; COELICOLOR; COILED-COILS; CRYSTAL-STRUCTURE; GENE; IDENTIFICATION; LECTIN; MYCOBACTERIUM-TUBERCULOSIS; PEPTIDOGLYCAN; SURFACE-PROTEINS; TEICHOIC-ACIDS | Erscheinungsdatum: | 2003 | Herausgeber: | ELSEVIER | Journal: | JOURNAL OF BIOLOGICAL CHEMISTRY | Volumen: | 278 | Ausgabe: | 29 | Startseite: | 26639 | Seitenende: | 26647 | Zusammenfassung: | Streptomyces reticuli produces a 34.6- kDa surface-anchored protein (AbpS) whose surface-exposed N terminus binds strongly to Avicel, a dominantly crystalline type of cellulose. The generation of a large set of mutated abpS-genes and the subsequent analysis of the corresponding proteins in vitro as well as in vivo in a Streptomyces host allow the assignment of the following characteristics for AbpS. (i) Amino acid residues participating directly in the cellulose-interaction are located at the N terminus. (ii) As ascertained by cross-linking experiments, AbpS forms homotetramers in its soluble as well as cellulose-bound form. (iii) The intermolecular assembly of four AbpS molecules is governed by two domains (including amino acids 60-110 and 161-212). Both domains possess large portions of alpha-helical regions in which hydrophobic amino acids are located on one side as known from coiled-coil proteins. (iv) The C-terminal part of AbpS comprising 35 amino acids contains a transmembrane domain. Due to the surface-exposed N terminus of AbpS and the presence of transmembrane helix the C terminus has to be situated in the cytoplasm of the S. reticuli hyphae. Thus AbpS connects the interior of the mycelia with the extracellular space and binds cellulose using a unique cellulose-binding module. |
DOI: | 10.1074/jbc.M212792200 |
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