English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

The genecelF of the crypticcel operon ofEscherichia coli has been cloned, and the encoded 6-phospho-β-glucosidase (cellobiose-6-phosphate [6P] hydrolase; CelF [EC3.2.1.86 ]) has been expressed and purified in a catalytically active state. Among phospho-β-glycosidases, CelF exhibits unique requirements for a divalent metal ion and NAD+ for activity and, by sequence alignment, is assigned to family 4 of the glycosylhydrolase superfamily. CelF hydrolyzed a variety of P-β-glucosides, including cellobiose-6P, salicin-6P, arbutin-6P, gentiobiose-6P, methyl-β-glucoside-6P, and the chromogenic analog,p -nitrophenyl-β-d -glucopyranoside-6P. In the absence of a metal ion and NAD+ , purified CelF was rapidly and irreversibly inactivated. The functional roles of the cofactors have not been established, but NAD+ appears not to be a reactant and there is no evidence for reduction of the nucleotide during substrate cleavage. In solution, native CelF exists as a homotetramer (M w , ∼200,000) composed of noncovalently linked subunits, and this oligomeric structure is maintained independently of the presence or absence of a metal ion. The molecular weight of the CelF monomer (M r , ∼50,000), estimated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, is in agreement with that calculated from the amino acid sequence of the polypeptide (450 residues;M r = 50,512). Comparative sequence alignments provide tentative identification of the NAD+ -binding domain (residues 7 to 40) and catalytically important glutamyl residues (Glu112 and Glu356 ) of CelF.

Cellobiose-6-Phosphate Hydrolase (CelF) of Escherichia coli : Characterization and Assignment to the Unusual Family 4 of Glycosylhydrolases