Disease relevance of celB

• Comparison of the encoded amino acid sequence to other known beta-glucanases reveals a small region of similarity to the encoded protein of the Clostridium thermocellum celB gene [1].
• A gene from this organism, designated celB, has been cloned in Escherichia coli as part of a bacteriophage lambda gene library [2].
• The combined use of the gusA marker gene and celB allowed the simultaneous detection of several Rhizobium strains on a plant, and multiple-strain occupancy of individual modules also could be easily detected [3].
• Two celB-expressing transposons were constructed for use in ecological studies of a variety of gram-negative bacteria [3].
• Another fragment, of 2.5 kb and carrying celB, was cloned in the shuttle-vector plasmid, pJKK3-1, and expressed in E. coli and Bacillus subtilis [4].

High impact information on celB

• The Mr of the purified enzyme was 50,000, which is in good agreement with the size of EGB deduced from the nucleotide sequence of the celB gene, coding for EGB [5].
• The cDNA designated celB from the anaerobic rumen fungus Neocallimastix patriciarum contained a single open reading frame of 1422 bp coding for a protein (CelB) of M(r) 53,070 [6].
• Unlike previous fungal cellulases, genomic celB was devoid of introns [6].
• These experiments showed that the A. xylinum celB gene could not complement the role of the bifunctional X. campestris phosphoglucomutase-phosphomannomutase gene in xanthan biosynthesis [7].
• The celB gene encoding the cellobiose-hydrolyzing enzyme beta-glucosidase from the hyperthermophilic archaeon Pyrococcus furiosus has been identified, cloned, and sequenced [8].

Chemical compound and disease context of celB

• The celB gene product synthesized in E. coli showed high activity on carboxymethyl cellulose and lichenan while low activity was found on Avicel [9].

Biological context of celB

• The colicin E2 immunity (ceiB) and lysis (celB) genes of colicin plasmid ColE2-P9 were cloned as a 900-base-pair insert under the control of the lac promoter in high-copy-number plasmid pUR222 [10].
• The results were consistent with the idea that expression of celB (production of the 5,000- and 3,000-molecular-weight proteins) is sufficient to cause host cell lysis in the absence of colicin production and derepression of the host cell SOS system [10].
• The noncoding region downstream from the mannanase gene showed strong homology to celB, a gene coding for a cellulase from the same organism, suggesting that the manA gene might have been inserted into its present position on the "C. saccharolyticum" genome by homologous recombination [11].
• A potential LexA binding site is located immediately upstream from ceaB, and a rho-independent terminator structure is located immediately downstream from celB [12].
• The operon comprises the colicin activity gene, ceaB, the colicin immunity gene, ceiB, and the lysis gene, celB, which is essential for colicin release from producing cells [12].

Associations of celB with chemical compounds

• Polyacrylamide gel electrophoresis showed that celB produced a protein with a molecular weight of 118,000 to 120,000 [2].
• Analysis of hydrolysis products from defined cellodextrins showed that the celB and celC enzymes hydrolysed beta-1,4-glucosidic linkages randomly, whereas the celA enzyme cleaved cellotetraose to cellobiose, and cellopentaose to cellobiose and cellotriose [13].

Other interactions of celB

• 1.5 kb and 1.2 kb fragments containing the celA and celB genes, respectively, were subcloned and sequenced [14].

Analytical, diagnostic and therapeutic context of celB

• After incubating the nitrocellulose blot with antiserum and subsequently with 125I-labeled protein A, a band with Mr 66,000, corresponding to the celB gene product expressed by C. thermocellum, was detected by autoradiography [15].

References