Search for a dextransucrase minimal motif involved in dextran binding.
Fourteen truncated forms of Leuconostoc mesenteroides NRRL B512-F dextransucrase, involving N-, C- or N- plus C-terminal domain truncations were tested for their ability to bind dextrans. The shortest fragment (14kDa molecular weight) that still exhibited a strong interaction with dextran was localized between amino acids N1397 and A1527 of the C-terminal domain (GBD-7) and consists of six YG repeats. With a dissociation constant K(d) of 2.8x10(-9)M, this motif shows a very high affinity for isomaltohexaose and longer dextrans, supporting the proposed role of GBD in polymer formation. The potential application of GBD-7 as an affinity tag onto cheap resins like Sephacryl S300HR for rapid purification was evaluated and is discussed.
Suwannarangsee
Surisa
S
Biological Science Program, Faculty of Science, Chulalongkorn University, 254 Phyathai Road, Patumwan, Bangkok, Thailand.
Moulis
Claire
C
Potocki-Veronese
Gabrielle
G
Monsan
Pierre
P
Remaud-Simeon
Magali
M
Chulalaksananukul
Warawut
W
D020816:Amino Acid Motifs; D003911:Dextrans / Q000378:metabolism*; D017353:Gene Deletion; D005936:Glucans / Q000378:metabolism; D005964:Glucosyltransferases / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D007934:Leuconostoc / Q000235:genetics / Q000378:metabolism; D008969:Molecular Sequence Data; D011485:Protein Binding; D016415:Sequence Alignment; D013879:Thioredoxins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism