1T4B

1.6 Angstrom structure of Esherichia coli aspartate-semialdehyde dehydrogenase.

Summary for 1T4B

• Entry DOI: 10.2210/pdb1t4b/pdb
• Related: 1T4D
• Descriptor: Aspartate-semialdehyde dehydrogenase, SODIUM ION (3 entities in total)
• Functional Keywords: asadh, aspartate semialdehyde dehydrogenase, hosr, lysine biosynthesis, nadp+ oxidoreductase (phosphorylating), domain movement, oxidoreductase
• Biological source: Escherichia coli
• Total number of polymer chains: 2
• Total formula weight: 80226.33

Authors

Nichols, C.E.,Dhaliwal, B.,Lockyer, M.,Hawkins, A.R.,Stammers, D.K. (deposition date: 2004-04-29, release date: 2004-07-13, Last modification date: 2023-08-23)

Primary citation

Nichols, C.E.,Dhaliwal, B.,Lockyer, M.,Hawkins, A.R.,Stammers, D.K.
High-resolution Structures Reveal Details of Domain Closure and "Half-of-sites-reactivity" in Escherichia coli Aspartate beta-Semialdehyde Dehydrogenase.
J.Mol.Biol., 341:797-806, 2004

PubMed Abstract: Two high-resolution structures have been determined for Eschericia coli aspartate beta-semialdehyde dehydrogenase (ecASADH), an enzyme of the aspartate biosynthetic pathway, which is a potential target for novel antimicrobial drugs. Both ASADH structures were of the open form and were refined to 1.95 A and 1.6 A resolution, allowing a more detailed comparison with the closed form of the enzyme than previously possible. A more complex scheme for domain closure is apparent with the subunit being split into two further sub-domains with relative motions about three hinge axes. Analysis of hinge data and torsion-angle difference plots is combined to allow the proposal of a detailed structural mechanism for ecASADH domain closure. Additionally, asymmetric distortions of individual subunits are identified, which form the basis for the previously reported "half-of-the-sites reactivity" (HOSR). A putative explanation of this arrangement is also presented, suggesting the HOSR system may provide a means for ecASADH to offset the energy required to remobilise flexible loops at the end of the reaction cycle, and hence avoid falling into an energy minimum.

PubMed: 15288787
DOI: 10.1016/j.jmb.2004.05.073

Experimental method

X-RAY DIFFRACTION (1.6 Å)