5HXM

Cycloalternan-forming enzyme from Listeria monocytogenes in complex with panose

Summary for 5HXM

• Entry DOI: 10.2210/pdb5hxm/pdb
• Related: 4KMQ 4KWU 5HPO
• Descriptor: Alpha-xylosidase, Cyclic alpha-D-glucopyranose-(1-6)-alpha-D-glucopyranose-(1-3)-alpha-D-glucopyranose-(1-6)-alpha-D-glucopyranose, alpha-D-glucopyranose-(1-6)-alpha-D-glucopyranose, ... (7 entities in total)
• Functional Keywords: center for structural genomics of infectious diseases, csgid, idp05250, lmo2446, listeria monocytogenes egd-e, hydrolase
• Biological source: Listeria monocytogenes
• Total number of polymer chains: 1
• Total formula weight: 123761.61

Authors

Halavaty, A.S.,Light, S.H.,Minasov, G.,Winsor, J.,Grimshaw, S.,Shuvalova, L.,Peterson, S.,Anderson, W.F.,Center for Structural Genomics of Infectious Diseases (CSGID) (deposition date: 2016-01-31, release date: 2017-01-25, Last modification date: 2024-10-23)

Primary citation

Light, S.H.,Cahoon, L.A.,Mahasenan, K.V.,Lee, M.,Boggess, B.,Halavaty, A.S.,Mobashery, S.,Freitag, N.E.,Anderson, W.F.
Transferase Versus Hydrolase: The Role of Conformational Flexibility in Reaction Specificity.
Structure, 25:295-304, 2017

PubMed Abstract: Active in the aqueous cellular environment where a massive excess of water is perpetually present, enzymes that catalyze the transfer of an electrophile to a non-water nucleophile (transferases) require specific strategies to inhibit mechanistically related hydrolysis reactions. To identify principles that confer transferase versus hydrolase reaction specificity, we exploited two enzymes that use highly similar catalytic apparatuses to catalyze the transglycosylation (a transferase reaction) or hydrolysis of α-1,3-glucan linkages in the cyclic tetrasaccharide cycloalternan (CA). We show that substrate binding to non-catalytic domains and a conformationally stable active site promote CA transglycosylation, whereas a distinct pattern of active site conformational change is associated with CA hydrolysis. These findings defy the classic view of induced-fit conformational change and illustrate a mechanism by which a stable hydrophobic binding site can favor transferase activity and disfavor hydrolysis. Application of these principles could facilitate the rational reengineering of transferases with desired catalytic properties.

PubMed: 28089449
DOI: 10.1016/j.str.2016.12.007

Experimental method

X-RAY DIFFRACTION (1.9 Å)