(Below N is a link to NCBI taxonomic web page and E link to ESTHER at designed phylum.) > cellular organisms: NE > Bacteria: NE > FCB group: NE > Bacteroidetes/Chlorobi group: NE > Bacteroidetes: NE > Bacteroidia: NE > Bacteroidales: NE > Prevotellaceae: NE > Prevotella: NE > Prevotella ruminicola: NE
LegendThis sequence has been compared to family alignement (MSA) red => minority aminoacid blue => majority aminoacid color intensity => conservation rate title => sequence position(MSA position)aminoacid rate Catalytic site Catalytic site in the MSA AETTVPGNEFPKVDKEGRAYFRIAAPEARKVVLDICNKKYDMQRDGKGNF MAVTDPLPVGFHYYFLNINGVNFIDPSTETFFGCNRESGGIEIPEGSEGD YYRPQQGVPAGQVRSIYYYSNEQQTWRHAMVYTPAEYELAKNAKKRYPVL YLQHGMGEDETGWSKQGHMQHIMDNAIAKGEAVPMIVVMESGDIKAPFGG GNNQAGRSAYGASFYPVLLNDLIPYIDSNYRTKSDRENRAMAGLSWGGHQ TFDVVLTNLDKFAWLGTFSGAIFGLDVKTAYDGVFANADEFNKKIHYMYM NWGEEDFIKSGDIVKQLRELGIKVDSNESKGTAHEWLTWRRGLNEFIPHL FKK
References
Title: Biochemical characterization and relative expression levels of multiple carbohydrate esterases of the xylanolytic rumen bacterium Prevotella ruminicola 23 grown on an ester-enriched substrate Kabel MA, Yeoman CJ, Han Y, Dodd D, Abbas CA, de Bont JA, Morrison M, Cann IK, Mackie RI Ref: Applied Environmental Microbiology, 77:5671, 2011 : PubMed
We measured expression and used biochemical characterization of multiple carbohydrate esterases by the xylanolytic rumen bacterium Prevotella ruminicola 23 grown on an ester-enriched substrate to gain insight into the carbohydrate esterase activities of this hemicellulolytic rumen bacterium. The P. ruminicola 23 genome contains 16 genes predicted to encode carbohydrate esterase activity, and based on microarray data, four of these were upregulated >2-fold at the transcriptional level during growth on an ester-enriched oligosaccharide (XOS(FA,Ac)) from corn relative to a nonesterified fraction of corn oligosaccharides (AXOS). Four of the 16 esterases (Xyn10D-Fae1A, Axe1-6A, AxeA1, and Axe7A), including the two most highly induced esterases (Xyn10D-Fae1A and Axe1-6A), were heterologously expressed in Escherichia coli, purified, and biochemically characterized. All four enzymes showed the highest activity at physiologically relevant pH (6 to 7) and temperature (30 to 40 degrees C) ranges. The P. ruminicola 23 Xyn10D-Fae1A (a carbohydrate esterase [CE] family 1 enzyme) released ferulic acid from methylferulate, wheat bran, corn fiber, and XOS(FA,Ac), a corn fiber-derived substrate enriched in O-acetyl and ferulic acid esters, but exhibited negligible activity on sugar acetates. As expected, the P. ruminicola Axe1-6A enzyme, which was predicted to possess two distinct esterase family domains (CE1 and CE6), released ferulic acid from the same substrates as Xyn10D-Fae1 and was also able to cleave O-acetyl ester bonds from various acetylated oligosaccharides (AcXOS). The P. ruminicola 23 AxeA1, which is not assigned to a CE family, and Axe7A (CE7) were found to be acetyl esterases that had activity toward a broad range of mostly nonpolymeric acetylated substrates along with AcXOS. All enzymes were inhibited by the proximal location of other side groups like 4-O-methylglucuronic acid, ferulic acid, or acetyl groups. The unique diversity of carbohydrate esterases in P. ruminicola 23 likely gives it the ability to hydrolyze substituents on the xylan backbone and enhances its capacity to efficiently degrade hemicellulose.
The Prevotellas comprise a diverse group of bacteria that has received surprisingly limited attention at the whole genome-sequencing level. In this communication, we present the comparative analysis of the genomes of Prevotella ruminicola 23 (GenBank: CP002006) and Prevotella bryantii B(1)4 (GenBank: ADWO00000000), two gastrointestinal isolates. Both P. ruminicola and P. bryantii have acquired an extensive repertoire of glycoside hydrolases that are targeted towards non-cellulosic polysaccharides, especially GH43 bifunctional enzymes. Our analysis demonstrates the diversity of this genus. The results from these analyses highlight their role in the gastrointestinal tract, and provide a template for additional work on genetic characterization of these species.
