TY - JOUR
T1 - Serine substitution for systeine residues in levansucrase selectively abolishes levan forming activity
AU - Senthilkumar, V
AU - Busby, Stephen
AU - Gunasekaran, P
PY - 2003/1/1
Y1 - 2003/1/1
N2 - Levansucrase is responsible for levan formation during sucrose fermentation of Zymomonas mobilis, and this decreases the efficiency of ethanol production. As thiol modifying agents decrease levan formation, a role for cysteine residues in levansucrase activity has been examined using derivatives of Z. mobilis levansucrase that carry serine substitutions of cysteine at positions 121, 151 or 244. These substitutions abolished the levan forming activity of levansucrase whilst only halving its activity in sucrose hydrolysis. Thus, polymerase and hydrolase activities of Z. mobilis levansucrase are separate and have different requirements for the enzyme's cysteine residues.
AB - Levansucrase is responsible for levan formation during sucrose fermentation of Zymomonas mobilis, and this decreases the efficiency of ethanol production. As thiol modifying agents decrease levan formation, a role for cysteine residues in levansucrase activity has been examined using derivatives of Z. mobilis levansucrase that carry serine substitutions of cysteine at positions 121, 151 or 244. These substitutions abolished the levan forming activity of levansucrase whilst only halving its activity in sucrose hydrolysis. Thus, polymerase and hydrolase activities of Z. mobilis levansucrase are separate and have different requirements for the enzyme's cysteine residues.
UR - http://www.scopus.com/inward/record.url?scp=0141638460&partnerID=8YFLogxK
U2 - 10.1023/A:1025650928313
DO - 10.1023/A:1025650928313
M3 - Article
C2 - 14584923
SN - 1573-6776
VL - 25
SP - 1653
EP - 1656
JO - Biotechnology Letters
JF - Biotechnology Letters
ER -