Document Type

Article

Publication Date

3-16-2021

Publication Title

Biochemistry

Volume

60

Issue

12

Pages

908–917

Publisher Name

ACS Publications

Abstract

We report the atomic-resolution (1.3 Å) X-ray crystal structure of an open conformation of the dapE-encoded N-succinyl-l,l-diaminopimelic acid desuccinylase (DapE, EC 3.5.1.18) from Neisseria meningitidis. This structure [Protein Data Bank (PDB) entry 5UEJ] contains two bound sulfate ions in the active site that mimic the binding of the terminal carboxylates of the N-succinyl-l,l-diaminopimelic acid (l,l-SDAP) substrate. We demonstrated inhibition of DapE by sulfate (IC50 = 13.8 ± 2.8 mM). Comparison with other DapE structures in the PDB demonstrates the flexibility of the interdomain connections of this protein. This high-resolution structure was then utilized as the starting point for targeted molecular dynamics experiments revealing the conformational change from the open form to the closed form that occurs when DapE binds l,l-SDAP and cleaves the amide bond. These simulations demonstrated closure from the open to the closed conformation, the change in RMS throughout the closure, and the independence in the movement of the two DapE subunits. This conformational change occurred in two phases with the catalytic domains moving toward the dimerization domains first, followed by a rotation of catalytic domains relative to the dimerization domains. Although there were no targeting forces, the substrate moved closer to the active site and bound more tightly during the closure event.

Comments

Author Posting © American Chemical Society, 2021. This article is posted here by permission of American Chemical Society for personal use, not for redistribution. The article was published in Biochemistry, Volume 60, Issue 12, March 2021, https://doi.org/10.1021/acs.biochem.0c00926

Creative Commons License

Creative Commons License
This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 3.0 License.

Available for download on Wednesday, March 16, 2022

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