6H35

Myxococcus xanthus MglA bound to GDP and Pi with mixed inactive and active switch region conformations

Summary for 6H35

• Entry DOI: 10.2210/pdb6h35/pdb
• Descriptor: Mutual gliding-motility protein MglA, GUANOSINE-5'-DIPHOSPHATE, PHOSPHATE ION, ... (5 entities in total)
• Functional Keywords: small gtpase in a mixed state, cytosolic protein
• Biological source: Myxococcus xanthus DK 1622
• Total number of polymer chains: 2
• Total formula weight: 47787.46

Authors

Varela, P.F.,Galicia, C.,Cherfils, J. (deposition date: 2018-07-17, release date: 2019-12-04, Last modification date: 2024-05-15)

Primary citation

Galicia, C.,Lhospice, S.,Varela, P.F.,Trapani, S.,Zhang, W.,Navaza, J.,Herrou, J.,Mignot, T.,Cherfils, J.
MglA functions as a three-state GTPase to control movement reversals of Myxococcus xanthus.
Nat Commun, 10:5300-5300, 2019

PubMed Abstract: In Myxococcus xanthus, directed movement is controlled by pole-to-pole oscillations of the small GTPase MglA and its GAP MglB. Direction reversals require that MglA is inactivated by MglB, yet paradoxically MglA and MglB are located at opposite poles at reversal initiation. Here we report the complete MglA/MglB structural cycle combined to GAP kinetics and in vivo motility assays, which uncovers that MglA is a three-state GTPase and suggests a molecular mechanism for concerted MglA/MglB relocalizations. We show that MglA has an atypical GTP-bound state (MglA-GTP*) that is refractory to MglB and is re-sensitized by a feedback mechanism operated by MglA-GDP. By identifying and mutating the pole-binding region of MglB, we then provide evidence that the MglA-GTP* state exists in vivo. These data support a model in which MglA-GDP acts as a soluble messenger to convert polar MglA-GTP* into a diffusible MglA-GTP species that re-localizes to the opposite pole during reversals.

PubMed: 31757955
DOI: 10.1038/s41467-019-13274-3

Experimental method

X-RAY DIFFRACTION (2.3 Å)