Cloning and comparison of third beta-glucoside utilization (bglEFIA) operon with two operons of Pectobacterium carotovorum subsp. carotovorum LY34.
A third bgl operon containing bglE, bglF, bglI, and bglA was isolated from Pectobacterium carotovorum subsp. carotovorum LY34 (Pcc LY34). The sequences of BglE, BglF, and Bgll were similar to those of the phosphotransferase system (PTS) components IIB, IIC, and IIA respectively. BglF contains important residues for the phosphotransferase system. The amino acid sequence of BglA showed high similarity to various 6-phospho-beta-glucosidases and to a member of glycosyl hydrolase family 1. Sequence and structural analysis also revealed that these four genes were organized in a putative operon that differed from two operons previously isolated from Pcc LY34, bglTPB (accession no. AY542524) and ascGFB (accession no. AY622309). The transcription regulator for this operon was not found, and the EII complexes for PTS were encoded separately by three genes (bglE, bglF, and bglI). The BglA enzyme had a molecular weight estimated to be 57,350 Da by SDS-PAGE. The purified beta-glucosidase hydrolyzed salicin, arbutin, rhoNPG, rhoNPbetaG6P, and MUG, exhibited maximal activity at pH 7.0 and 40 degrees C, and displayed enhanced activity in the presence of Mg2+ and Ca2+. Two glutamate residues (Glu178 and Glu378) were found to be essential for enzyme activity.
Hong
Su Young
SY
Division of Applied Life Science, Gyeongsang National University, Chinju, Korea.
An
Chang Long
CL
Cho
Kye Man
KM
Lee
Sun Mi
SM
Kim
Yong Hee
YH
Kim
Min Keun
MK
Cho
Soo Jeong
SJ
Lim
Yong Pyo
YP
Kim
Hoon
H
Yun
Han Dae
HD
D000595:Amino Acid Sequence; D001483:Base Sequence; D002412:Cations / Q000737:chemistry; D003001:Cloning, Molecular; D017124:Conserved Sequence; D004795:Enzyme Stability; D005959:Glucosidases / Q000737:chemistry / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism*; D005960:Glucosides / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008670:Metals / Q000737:chemistry / Q000494:pharmacology; D008969:Molecular Sequence Data; D009154:Mutation / Q000235:genetics; D009876:Operon / Q000235:genetics*; D016973:Pectobacterium carotovorum / Q000145:classification / Q000201:enzymology* / Q000235:genetics*; D010770:Phosphotransferases / Q000378:metabolism; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D013696:Temperature
D002412:Cations; D005960:Glucosides; D008670:Metals; D010770:Phosphotransferases; D005959:Glucosidases; C066586:6-phospho-beta-glucosidase