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Structure of the adenylation domain Thr1 involved in the biosynthesis of 4-chlorothreonine in Streptomyces sp. OH-5093-protein flexibility and molecular bases of substrate specificity.

Authors :
Scaglione, Antonella
Fullone, Maria Rosaria
Montemiglio, Linda Celeste
Parisi, Giacomo
Zamparelli, Carlotta
Vallone, Beatrice
Savino, Carmelinda
Grgurina, Ingeborg
Source :
FEBS Journal. Sep2017, Vol. 284 Issue 18, p2981-2999. 19p.
Publication Year :
2017

Abstract

We determined the crystal structure of Thr1, the self-standing adenylation domain involved in the nonribosomal-like biosynthesis of free 4-chlorothreonine in Streptomyces sp. OH-5093. Thr1 shows two monomers in the crystallographic asymmetric unit with different relative orientations of the C- and N-terminal subdomains both in the presence of substrates and in the unliganded form. Cocrystallization with substrates, adenosine 5′-triphosphate and l-threonine, yielded one monomer containing the two substrates and the other in complex with l-threonine adenylate, locked in a postadenylation state. Steady-state kinetics showed that Thr1 activates l-Thr and its stereoisomers, as well as d-Ala, l- and d-Ser, albeit with lower efficiency. Modeling of these substrates in the active site highlighted the molecular bases of substrate discrimination. This work provides the first crystal structure of a threonine-activating adenylation enzyme, a contribution to the studies on conformational rearrangement in adenylation domains and on substrate recognition in nonribosomal biosynthesis. Database Structural data are available in the Protein Data Bank under the accession number and . [ABSTRACT FROM AUTHOR]

Details

Language :
English
ISSN :
1742464X
Volume :
284
Issue :
18
Database :
Academic Search Index
Journal :
FEBS Journal
Publication Type :
Academic Journal
Accession number :
125199641
Full Text :
https://doi.org/10.1111/febs.14163