 |
PDBsum entry 4lpc
|
|
|
|
References listed in PDB file
|
 |
|
Key reference
|
|
|
Title
|
|
Crystal structures of escherichia coli branching enzyme in complex with linear oligosaccharides.
|
|
|
Authors
|
|
L.Feng,
R.Fawaz,
S.Hovde,
L.Gilbert,
J.Chiou,
J.H.Geiger.
|
|
|
Ref.
|
|
Biochemistry, 2015,
54,
6207-6218.
[DOI no: ]
|
|
|
PubMed id
|
|
|
|
|
|
|
|
|
Abstract
|
|
|
Branching enzyme is responsible for all branching of glycogen and starch. It is
an unusual member of the α-amylase family because it has both α-1,4-amylase
activity and α-1,6-transferase activity [Drummond, G. S., et al. (1972) Eur. J.
Biochem. 26, 168-176]. It also does not react with shorter glucans, though it
will bind much longer substrates and substrate mimics [Binderup, K., et al.
(2002) Arch. Biochem. Biophys. 397, 279-285]. In an effort to better understand
how branching enzyme interacts with its polymeric substrate, we have determined
the structure of Δ112 Escherichia coli branching enzyme bound to maltoheptaose
and maltohexaose. Together, these structures define six distinct oligosaccharide
binding sites on the surface of E. coli branching enzyme. Most of these binding
sites surround the edge of the β-barrel domain and are quite far from the
active site. Surprisingly, there is no evidence of oligosaccharide binding in
the active site of the enzyme. The closest bound oligosaccharide resides almost
18 Å from the active site. Mutations to conserved residues in binding sites I
and VI had a debilitating effect on the activity of the enzyme.
|
|
|
|
|
|
|
