| Structural highlights
Function
[DRRA_LEGPN] Virulence effector that plays a key role in hijacking the host vesicular trafficking by recruiting the small guanosine triphosphatase (GTPase) Rab1 to the cytosolic face of the Legionella-containing vacuole (LCVs). Acts as a GDP-GTP exchange factor (GEF) for the small GTPase Rab1 (RAB1A, RAB1B or RAB1C), thereby converting Rab1 to an active GTP-bound state, leading to the incorporation of Rab1 into LCVs. Also shows RabGDI displacement factor (GDF) activity; however, this probably represents a passive activity following the GEF activity. Also acts as an adenylyltransferase by mediating the addition of adenosine 5'-monophosphate (AMP) to 'Tyr-77' of host RAB1B, thereby rendering RAB1B constitutively active. Also has adenylyltransferase activity towards Rab6 and Rab35. Also displays guanylyltransferase activity by mediating the addition of guanosine 5'-monophosphate (GMP) to host RAB1B in vitro; however such activity remains uncertain in vivo. Specifically binds phosphatidylinositol 4-phosphate (PtdIns(4)P) lipids on the cytosolic surface of the phagosomal membrane shortly after infection.[1] [2] [3] [RAB1B_HUMAN] Protein transport. Regulates vesicular transport between the endoplasmic reticulum and successive Golgi compartments.[4]
Publication Abstract from PubMed
The characterization of low-affinity protein complexes is challenging due to their dynamic nature. Here we present a method to stabilize transient protein complexes in vivo by generating a covalent and conformationally flexible bridge between the interaction partners. A highly active pyrrolysyl tRNA synthetase mutant directs the incorporation of unnatural amino acids bearing bromoalkyl moieties (BrCnK) into proteins. We demonstrate for the first time that low-affinity protein complexes between BrCnK-containing proteins and their binding partners can be stabilized in vivo in bacterial and mammalian cells. Using this approach we determined the crystal structure of a transient GDP-bound complex between a small G-protein and its nucleotide exchange factor. We envision that this approach will prove valuable as a general tool for validating and characterizing protein-protein interactions in vitro and in vivo.
Proximity-triggered covalent stabilization of low-affinity protein complexes in vitro and in vivo.,Cigler M, Muller TG, Horn-Ghetko D, von Wrisberg MK, Fottner M, Goody RS, Itzen A, Muller MP, Lang K Angew Chem Int Ed Engl. 2017 Sep 28. doi: 10.1002/anie.201706927. PMID:28960788[5]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Murata T, Delprato A, Ingmundson A, Toomre DK, Lambright DG, Roy CR. The Legionella pneumophila effector protein DrrA is a Rab1 guanine nucleotide-exchange factor. Nat Cell Biol. 2006 Sep;8(9):971-7. Epub 2006 Aug 13. PMID:16906144 doi:10.1038/ncb1463
- ↑ Ingmundson A, Delprato A, Lambright DG, Roy CR. Legionella pneumophila proteins that regulate Rab1 membrane cycling. Nature. 2007 Nov 15;450(7168):365-9. Epub 2007 Oct 21. PMID:17952054 doi:10.1038/nature06336
- ↑ Muller MP, Peters H, Blumer J, Blankenfeldt W, Goody RS, Itzen A. The Legionella effector protein DrrA AMPylates the membrane traffic regulator Rab1b. Science. 2010 Aug 20;329(5994):946-9. Epub 2010 Jul 22. PMID:20651120 doi:10.1126/science.1192276
- ↑ Overmeyer JH, Wilson AL, Erdman RA, Maltese WA. The putative "switch 2" domain of the Ras-related GTPase, Rab1B, plays an essential role in the interaction with Rab escort protein. Mol Biol Cell. 1998 Jan;9(1):223-35. PMID:9437002
- ↑ Cigler M, Muller TG, Horn-Ghetko D, von Wrisberg MK, Fottner M, Goody RS, Itzen A, Muller MP, Lang K. Proximity-triggered covalent stabilization of low-affinity protein complexes in vitro and in vivo. Angew Chem Int Ed Engl. 2017 Sep 28. doi: 10.1002/anie.201706927. PMID:28960788 doi:http://dx.doi.org/10.1002/anie.201706927
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