7TVH

Hyperlytic variant of Tae1, Type VI secretion amidase effector 1, from Pseudomonas aeruginosa (Cys110Ser)

Summary for 7TVH

• Entry DOI: 10.2210/pdb7tvh/pdb
• Descriptor: Peptidoglycan amidase Tse1 (2 entities in total)
• Functional Keywords: type vi secretion amidase effector, tae1 hyperlytic variant, cys110ser, antimicrobial protein, hydrolase
• Biological source: Pseudomonas aeruginosa (strain ATCC 15692 / DSM 22644 / CIP 104116 / JCM 14847 / LMG 12228 / 1C / PRS 101 / PAO1)
• Total number of polymer chains: 4
• Total formula weight: 70055.05

Authors

Radkov, A.,Saunders, H.,Chou, S. (deposition date: 2022-02-04, release date: 2022-07-06, Last modification date: 2024-11-06)

Primary citation

Radkov, A.,Sapiro, A.L.,Flores, S.,Henderson, C.,Saunders, H.,Kim, R.,Massa, S.,Thompson, S.,Mateusiak, C.,Biboy, J.,Zhao, Z.,Starita, L.M.,Hatleberg, W.L.,Vollmer, W.,Russell, A.B.,Simorre, J.P.,Anthony-Cahill, S.,Brzovic, P.,Hayes, B.,Chou, S.
Antibacterial potency of type VI amidase effector toxins is dependent on substrate topology and cellular context.
Elife, 11:-, 2022

PubMed Abstract: Members of the bacterial 6SS midase ffector (Tae) superfamily of toxins are delivered between competing bacteria to degrade cell wall peptidoglycan. Although Taes share a common substrate, they exhibit distinct antimicrobial potency across different competitor species. To investigate the molecular basis governing these differences, we quantitatively defined the functional determinants of Tae1 from PAO1 using a combination of nuclear magnetic resonance and a high-throughput in vivo genetic approach called deep mutational scanning (DMS). As expected, combined analyses confirmed the role of critical residues near the Tae1 catalytic center. Unexpectedly, DMS revealed substantial contributions to enzymatic activity from a much larger, ring-like functional hot spot extending around the entire circumference of the enzyme. Comparative DMS across distinct growth conditions highlighted how functional contribution of different surfaces is highly context-dependent, varying alongside composition of targeted cell walls. These observations suggest that Tae1 engages with the intact cell wall network through a more distributed three-dimensional interaction interface than previously appreciated, providing an explanation for observed differences in antimicrobial potency across divergent Gram-negative competitors. Further binding studies of several Tae1 variants with their cognate immunity protein demonstrate that requirements to maintain protection from Tae activity may be a significant constraint on the mutational landscape of toxicity in the wild. In total, our work reveals that Tae diversification has likely been shaped by multiple independent pressures to maintain interactions with binding partners that vary across bacterial species and conditions.

PubMed: 35762582
DOI: 10.7554/eLife.79796

Experimental method

X-RAY DIFFRACTION (1.71 Å)