Structural insight into the membrane targeting domain of the Legionella deAMPylase SidD

DOI: 10.1371/journal.ppat.1008734

Authors: Igor Tascon (CIC bioGUNE, Basque Research and Technology Alliance (BRTA)) , Xiao Li (Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health) , María Lucas (CIC bioGUNE, Basque Research and Technology Alliance (BRTA)) , D’anna Nelson (Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health) , Ander Vidaurrazaga (CIC bioGUNE, Basque Research and Technology Alliance (BRTA)) , Yi-Han Lin (Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health) , Adriana L. Rojas (CIC bioGUNE, Basque Research and Technology Alliance (BRTA)) , Aitor Hierro (CIC bioGUNE, Basque Research and Technology Alliance (BRTA)) , Matthias P. Machner (Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Plos Pathogens , VOL 16

State: Published (Approved)
Published: August 2020
Diamond Proposal Number(s): 20113

Abstract: AMPylation, the post-translational modification with adenosine monophosphate (AMP), is catalyzed by effector proteins from a variety of pathogens. Legionella pneumophila is thus far the only known pathogen that, in addition to encoding an AMPylase (SidM/DrrA), also encodes a deAMPylase, called SidD, that reverses SidM-mediated AMPylation of the vesicle transport GTPase Rab1. DeAMPylation is catalyzed by the N-terminal phosphatase-like domain of SidD. Here, we determined the crystal structure of full length SidD including the uncharacterized C-terminal domain (CTD). A flexible loop rich in aromatic residues within the CTD was required to target SidD to model membranes in vitro and to the Golgi apparatus within mammalian cells. Deletion of the loop (Δloop) or substitution of its aromatic phenylalanine residues rendered SidD cytosolic, showing that the hydrophobic loop is the primary membrane-targeting determinant of SidD. Notably, deletion of the two terminal alpha helices resulted in a CTD variant incapable of discriminating between membranes of different composition. Moreover, a L. pneumophila strain producing SidDΔloop phenocopied a L. pneumophila ΔsidD strain during growth in mouse macrophages and displayed prolonged co-localization of AMPylated Rab1 with LCVs, thus revealing that membrane targeting of SidD via its CTD is a critical prerequisite for its ability to catalyze Rab1 deAMPylation during L. pneumophila infection.

Journal Keywords: Legionella pneumophila; Crystal structure; Transfection; Liposomes; Cell membranes; Lipids; Guanosine triphosphatase; Golgi apparatus

Diamond Keywords: Legionnaires' Disease; Bacteria

Subject Areas: Biology and Bio-materials, Chemistry


Instruments: B21-High Throughput SAXS , I02-Macromolecular Crystallography

Added On: 09/09/2020 10:06

Discipline Tags:

Pathogens Infectious Diseases Health & Wellbeing Biochemistry Chemistry Structural biology Life Sciences & Biotech

Technical Tags:

Diffraction Scattering Macromolecular Crystallography (MX) Small Angle X-ray Scattering (SAXS)