Abstract
This research describes four X-ray structures of Vibrio harveyi chitinase A and its catalytically inactive mutant (E315M) in the presence and absence of substrates. The overall structure of chitinase A is that of a typical family-18 glycosyl hydrolase comprising three distinct domains: (i) the amino-terminal chitin-binding domain; (ii) the main catalytic (α/β)8 TIM-barrel domain; and (iii) the small (α + β) insertion domain. The catalytic cleft of chitinase A has a long, deep groove, which contains six chitooligosaccharide ring-binding subsites (-4)(-3)(-2)(-1)(+1)(+2). The binding cleft of the ligand-free E315M is partially blocked by the C-terminal (His)6-tag. Structures of E315M-chitooligosaccharide complexes display a linear conformation of pentaNAG, but a bent conformation of hexaNAG. Analysis of the final 2Fo - Fc omit map of E315M-NAG6 reveals the existence of the linear conformation of the hexaNAG at a lower occupancy with respect to the bent conformation. These crystallographic data provide evidence that the interacting sugars undergo conformational changes prior to hydrolysis by the wild-type enzyme.
| Original language | English |
|---|---|
| Pages (from-to) | 491-499 |
| Number of pages | 9 |
| Journal | Journal of Structural Biology |
| Volume | 162 |
| Issue number | 3 |
| DOIs | |
| Publication status | Published - Jun 1 2008 |
| Externally published | Yes |
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Keywords
- Chitin oligosaccharide
- Chitinase
- Crystal structure
- The slide-and-bend mechanism
- Vibrio harveyi
ASJC Scopus subject areas
- Structural Biology
Cite this
Crystal structures of Vibrio harveyi chitinase A complexed with chitooligosaccharides : Implications for the catalytic mechanism. / Songsiriritthigul, Chomphunuch; Pantoom, Supansa; Aguda, Adeleke H.; Robinson, Robert C.; Suginta, Wipa.
In: Journal of Structural Biology, Vol. 162, No. 3, 01.06.2008, p. 491-499.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Crystal structures of Vibrio harveyi chitinase A complexed with chitooligosaccharides
T2 - Implications for the catalytic mechanism
AU - Songsiriritthigul, Chomphunuch
AU - Pantoom, Supansa
AU - Aguda, Adeleke H.
AU - Robinson, Robert C.
AU - Suginta, Wipa
PY - 2008/6/1
Y1 - 2008/6/1
N2 - This research describes four X-ray structures of Vibrio harveyi chitinase A and its catalytically inactive mutant (E315M) in the presence and absence of substrates. The overall structure of chitinase A is that of a typical family-18 glycosyl hydrolase comprising three distinct domains: (i) the amino-terminal chitin-binding domain; (ii) the main catalytic (α/β)8 TIM-barrel domain; and (iii) the small (α + β) insertion domain. The catalytic cleft of chitinase A has a long, deep groove, which contains six chitooligosaccharide ring-binding subsites (-4)(-3)(-2)(-1)(+1)(+2). The binding cleft of the ligand-free E315M is partially blocked by the C-terminal (His)6-tag. Structures of E315M-chitooligosaccharide complexes display a linear conformation of pentaNAG, but a bent conformation of hexaNAG. Analysis of the final 2Fo - Fc omit map of E315M-NAG6 reveals the existence of the linear conformation of the hexaNAG at a lower occupancy with respect to the bent conformation. These crystallographic data provide evidence that the interacting sugars undergo conformational changes prior to hydrolysis by the wild-type enzyme.
AB - This research describes four X-ray structures of Vibrio harveyi chitinase A and its catalytically inactive mutant (E315M) in the presence and absence of substrates. The overall structure of chitinase A is that of a typical family-18 glycosyl hydrolase comprising three distinct domains: (i) the amino-terminal chitin-binding domain; (ii) the main catalytic (α/β)8 TIM-barrel domain; and (iii) the small (α + β) insertion domain. The catalytic cleft of chitinase A has a long, deep groove, which contains six chitooligosaccharide ring-binding subsites (-4)(-3)(-2)(-1)(+1)(+2). The binding cleft of the ligand-free E315M is partially blocked by the C-terminal (His)6-tag. Structures of E315M-chitooligosaccharide complexes display a linear conformation of pentaNAG, but a bent conformation of hexaNAG. Analysis of the final 2Fo - Fc omit map of E315M-NAG6 reveals the existence of the linear conformation of the hexaNAG at a lower occupancy with respect to the bent conformation. These crystallographic data provide evidence that the interacting sugars undergo conformational changes prior to hydrolysis by the wild-type enzyme.
KW - Chitin oligosaccharide
KW - Chitinase
KW - Crystal structure
KW - The slide-and-bend mechanism
KW - Vibrio harveyi
UR - http://www.scopus.com/inward/record.url?scp=44649153432&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=44649153432&partnerID=8YFLogxK
U2 - 10.1016/j.jsb.2008.03.008
DO - 10.1016/j.jsb.2008.03.008
M3 - Article
C2 - 18467126
AN - SCOPUS:44649153432
VL - 162
SP - 491
EP - 499
JO - Journal of Structural Biology
JF - Journal of Structural Biology
SN - 1047-8477
IS - 3
ER -