6EX0

Crystal structure of RelP (SAS2) from Staphylococcus aureus bound to pppGpp in the post-catalytic state

Summary for 6EX0

• Entry DOI: 10.2210/pdb6ex0/pdb
• Descriptor: GTP pyrophosphokinase, guanosine 5'-(tetrahydrogen triphosphate) 3'-(trihydrogen diphosphate), FE (II) ION, ... (4 entities in total)
• Functional Keywords: stringent response, (p)ppgpp, persistence, small alarmone synthetase, transferase
• Biological source: Staphylococcus aureus
• Total number of polymer chains: 2
• Total formula weight: 57610.40

Authors

Manav, M.C.,Brodersen, D.E. (deposition date: 2017-11-07, release date: 2018-01-24, Last modification date: 2024-01-17)

Primary citation

Manav, M.C.,Beljantseva, J.,Bojer, M.S.,Tenson, T.,Ingmer, H.,Hauryliuk, V.,Brodersen, D.E.
Structural basis for (p)ppGpp synthesis by theStaphylococcus aureussmall alarmone synthetase RelP.
J. Biol. Chem., 293:3254-3264, 2018

PubMed Abstract: The stringent response is a global reprogramming of bacterial physiology that renders cells more tolerant to antibiotics and induces virulence gene expression in pathogens in response to stress. This process is driven by accumulation of the intracellular alarmone guanosine-5'-di(tri)phosphate-3'-diphosphate ((p)ppGpp), which is produced by enzymes of the RelA SpoT homologue (RSH) family. The Gram-positive Firmicute pathogen, , encodes three RSH enzymes: a multidomain RSH (Rel) that senses amino acid starvation on the ribosome and two small alarmone synthetase (SAS) enzymes, RelQ (SAS1) and RelP (SAS2). In , RelQ (SAS1) was shown to form a tetramer that is activated by pppGpp and inhibited by single-stranded RNA, but the structural and functional regulation of RelP (SAS2) is unexplored. Here, we present crystal structures of RelP in two major functional states, pre-catalytic (bound to GTP and the non-hydrolyzable ATP analogue, adenosine 5'-(α,β-methylene)triphosphate (AMP-CPP)), and post-catalytic (bound to pppGpp). We observed that RelP also forms a tetramer, but unlike RelQ (SAS1), it is strongly inhibited by both pppGpp and ppGpp and is insensitive to inhibition by RNA. We also identified putative metal ion-binding sites at the subunit interfaces that were consistent with the observed activation of the enzyme by Zn ions. The structures reported here reveal the details of the catalytic mechanism of SAS enzymes and provide a molecular basis for understanding differential regulation of SAS enzymes in Firmicute bacteria.

PubMed: 29326162
DOI: 10.1074/jbc.RA117.001374

Experimental method

X-RAY DIFFRACTION (2.78 Å)