5E96

Crystal structure of aminoglycoside 6'-acetyltransferase type Ii

Summary for 5E96

• Entry DOI: 10.2210/pdb5e96/pdb
• Related: 1B87 1N71
• Descriptor: Aminoglycoside 6'-acetyltransferase, PHOSPHATE ION, 1,2-ETHANEDIOL, ... (4 entities in total)
• Functional Keywords: gnat, acetyltransferase, aminoglycoside resistance, transferase
• Biological source: Enterococcus faecium
• Total number of polymer chains: 1
• Total formula weight: 20672.03

Authors

Berghuis, A.M.,Burk, D.L.,Baettig, O.M.,Shi, K. (deposition date: 2015-10-14, release date: 2016-07-06, Last modification date: 2023-09-27)

Primary citation

Baettig, O.M.,Shi, K.,Yachnin, B.J.,Burk, D.L.,Berghuis, A.M.
Comprehensive characterization of ligand-induced plasticity changes in a dimeric enzyme.
Febs J., 283:3029-3038, 2016

PubMed Abstract: An enzyme's inherent structural plasticity is frequently associated with substrate binding, yet detailed structural characterization of flexible proteins remains challenging. This study employs complementary biophysical methods to characterize the partially unfolded structure of substrate-free AAC(6')-Ii, an N-acetyltransferase of the GCN5-related N-acetyltransferase (GNAT) superfamily implicated in conferring broad-spectrum aminoglycoside resistance on Enterococcus faecium. The X-ray crystal structure of AAC(6')-Ii is analyzed to identify relative motions of the structural elements that constitute the dimeric enzyme. Comparison with the previously elucidated crystal structure of AAC(6')-Ii with acetyl coenzyme A (AcCoA) reveals conformational changes that occur upon substrate binding. Our understanding of the enzyme's structural plasticity is further refined with small-angle X-ray scattering and circular dichroism analyses, which together reveal how flexible structural elements impact dimerization and substrate binding. These results clarify the extent of unfolding that AAC(6')-Ii undergoes in the absence of AcCoA and provide a structural connection to previously observed allosteric cooperativity of this enzyme.

PubMed: 27333541
DOI: 10.1111/febs.13788

Experimental method

X-RAY DIFFRACTION (2.1 Å)