Proteolytic release of the intramolecular chaperone domain confers processivity to endosialidase F

Medientyp: Sonstige Veröffentlichung; E-Artikel

Titel: Proteolytic release of the intramolecular chaperone domain confers processivity to endosialidase F

Beteiligte: Schwarzer, David [VerfasserIn]; Stummeyer, Katharina [VerfasserIn]; Haselhorst, Thomas [VerfasserIn]; Freiberger, Friedrich [VerfasserIn]; Rode, Bastian [VerfasserIn]; Grove, Melanie [VerfasserIn]; Scheper, Thomas [VerfasserIn]; Itzstein, Mark von [VerfasserIn]; Mühlenhoff, Martina [VerfasserIn]; Gerardy-Schahn, Rita [VerfasserIn]

Erschienen: Bethesda, Md. : ASBMB Publications, 2009

Ausgabe: published Version

Sprache: Englisch

DOI: https://doi.org/10.15488/16155; https://doi.org/10.1074/jbc.m808475200

ISSN: 0021-9258

Schlagwörter: Kinetics ; Binding Sites ; Carbohydrate Sequence ; Enzyme Activation ; Molecular ; Models

Entstehung:

Anmerkungen: Diese Datenquelle enthält auch Bestandsnachweise, die nicht zu einem Volltext führen.

Beschreibung: Endosialidases (endoNs), as identified so far, are tailspike proteins of bacteriophages that specifically bind and degrade the α2,8-linked polysialic acid (polySia) capsules of their hosts. The crystal structure solved for the catalytic domain of endoN from coliphage K1F (endoNF) revealed a functional trimer. Folding of the catalytic trimer is mediated by an intramolecular C-terminal chaperone domain. Release of the chaperone from the folded protein confers kinetic stability to endoNF. In mutant c(S), the replacement of serine 911 by alanine prevents proteolysis and generates an enzyme that varies in activity from wild type. Using soluble polySia as substrate a 3-times higher activity was detected while evaluation with immobilized polySia revealed a 190-fold reduced activity. Importantly, activity of c(S) did not differ from wild type with tetrameric sialic acid, the minimal endoNF substrate. Furthermore, we show that the presence of the chaperone domain in c(S) destabilizes binding to polySia in a similar way as did selective disruption of a polySia binding site in the stalk domain. The improved catalytic efficiency toward soluble polySia observed in these mutants can be explained by higher dissociation and association probabilities, whereas inversely, an impaired processivity was found. The fact that endoNF is a processive enzyme introduces a new molecular basis to explain capsule degradation by bacteriophages, which until now has been regarded as a result of cooperative interaction of tailspike proteins. Moreover, knowing that release of the chaperone domain confers kinetic stability and processivity, conservation of the proteolytic process can be explained by its importance in phage evolution. © 2009 by The American Society for Biochemistry and Molecular Biology, Inc.

Zugangsstatus: Freier Zugang

Proteolytic release of the intramolecular chaperone domain confers processivity to endosialidase F - [published Version]

Merkliste

Nur in Feld suchen:

Zuletzt gesuchte Begriffe: