TY  - JOUR
AU  - Syson, Karl
AU  - Stevenson, Clare E. M.
AU  - Rashid, Abdul M.
AU  - Saalbach, Gerhard
AU  - Tang, Minhong
AU  - Tuukkanen, Anne
AU  - Svergun, Dmitri
AU  - Withers, Stephen G.
AU  - Lawson, David M.
AU  - Bornemann, Stephen
TI  - Structural Insight into How Streptomyces coelicolor Maltosyl Transferase GlgE Binds α-Maltose 1-Phosphate and Forms a Maltosyl-Enzyme Intermediate
JO  - Biochemistry
VL  - 53
IS  - 15
SN  - 1520-4995
CY  - Columbus, Ohio
PB  - American Chemical Society
M1  - PUBDB-2015-01352
SP  - 2494 - 2504
PY  - 2014
AB  - GlgE (EC 2.4.99.16) is an α-maltose 1-phosphate:(1→4)-α- D -glucan 4-α- D -maltosyltransferase of theCAZy glycoside hydrolase 13_3 family. It is the definingenzyme of a bacterial α-glucan biosynthetic pathway and is agenetically validated anti-tuberculosis target. It catalyzes the α-retaining transfer of maltosyl units from α-maltose 1-phosphate to maltooligosaccharides and is predicted to use adouble-displacement mechanism. Evidence of this mechanismwas obtained using a combination of site-directed mutagenesis of Streptomyces coelicolor GlgE isoform I, substrate analogues,protein crystallography, and mass spectrometry. The X-ray structures of α-maltose 1-phosphate bound to a D394A mutein and aβ-2-deoxy-2-fluoromaltosyl-enzyme intermediate with a E423A mutein were determined. There are few examples of CAZyglycoside hydrolase family 13 members that have had their glycosyl-enzyme intermediate structures determined, and none beforenow have been obtained with a 2-deoxy-2-fluoro substrate analogue. The covalent modification of Asp394 was confirmed usingmass spectrometry. A similar modification of wild-type GlgE proteins from S. coelicolor and Mycobacterium tuberculosis was alsoobserved. Small-angle X-ray scattering of the M. tuberculosis enzyme revealed a homodimeric assembly similar to that of the S.coelicolor enzyme but with slightly differently oriented monomers. The deeper understanding of the structure−functionrelationships of S. coelicolor GlgE will aid the development of inhibitors of the M. tuberculosis enzyme.
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000334991100008
C6  - pmid:24689960
DO  - DOI:10.1021/bi500183c
UR  - https://bib-pubdb1.desy.de/record/207454
ER  -