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Structural characterization of Myxococcus xanthus MglC, a component of the polarity control system, and its interactions with its paralog MglB

The δ-proteobacteria Myxococcus xanthus displays social (S) and adventurous (A) motilities, which require pole-to-pole reversal of the motility regulator proteins. Mutual gliding motility protein C (MglC), a paralog of GTPase-activating protein Mutual gliding motility protein B (MglB), is a member o...

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Autores principales: Kapoor, Srajan, Kodesia, Akriti, Kalidas, Nidhi, Ashish, Thakur, Krishan Gopal
Formato: Online Artículo Texto
Lenguaje:English
Publicado: American Society for Biochemistry and Molecular Biology 2021
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7949163/
https://www.ncbi.nlm.nih.gov/pubmed/33493516
http://dx.doi.org/10.1016/j.jbc.2021.100308
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author Kapoor, Srajan
Kodesia, Akriti
Kalidas, Nidhi
Ashish
Thakur, Krishan Gopal
author_facet Kapoor, Srajan
Kodesia, Akriti
Kalidas, Nidhi
Ashish
Thakur, Krishan Gopal
author_sort Kapoor, Srajan
collection PubMed
description The δ-proteobacteria Myxococcus xanthus displays social (S) and adventurous (A) motilities, which require pole-to-pole reversal of the motility regulator proteins. Mutual gliding motility protein C (MglC), a paralog of GTPase-activating protein Mutual gliding motility protein B (MglB), is a member of the polarity module involved in regulating motility. However, little is known about the structure and function of MglC. Here, we determined ∼1.85 Å resolution crystal structure of MglC using Selenomethionine Single-wavelength anomalous diffraction. The crystal structure revealed that, despite sharing <9% sequence identity, both MglB and MglC adopt a Regulatory Light Chain 7 family fold. However, MglC has a distinct ∼30° to 40° shift in the orientation of the functionally important α2 helix compared with other structural homologs. Using isothermal titration calorimetry and size-exclusion chromatography, we show that MglC binds MglB in 2:4 stoichiometry with submicromolar range dissociation constant. Using small-angle X-ray scattering and molecular docking studies, we show that the MglBC complex consists of a MglC homodimer sandwiched between two homodimers of MglB. A combination of size-exclusion chromatography and site-directed mutagenesis studies confirmed the MglBC interacting interface obtained by molecular docking studies. Finally, we show that the C-terminal region of MglB, crucial for binding its established partner MglA, is not required for binding MglC. These studies suggest that the MglB uses distinct interfaces to bind MglA and MglC. Based on these data, we propose a model suggesting a new role for MglC in polarity reversal in M. xanthus.
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spelling pubmed-79491632021-03-19 Structural characterization of Myxococcus xanthus MglC, a component of the polarity control system, and its interactions with its paralog MglB Kapoor, Srajan Kodesia, Akriti Kalidas, Nidhi Ashish Thakur, Krishan Gopal J Biol Chem Research Article The δ-proteobacteria Myxococcus xanthus displays social (S) and adventurous (A) motilities, which require pole-to-pole reversal of the motility regulator proteins. Mutual gliding motility protein C (MglC), a paralog of GTPase-activating protein Mutual gliding motility protein B (MglB), is a member of the polarity module involved in regulating motility. However, little is known about the structure and function of MglC. Here, we determined ∼1.85 Å resolution crystal structure of MglC using Selenomethionine Single-wavelength anomalous diffraction. The crystal structure revealed that, despite sharing <9% sequence identity, both MglB and MglC adopt a Regulatory Light Chain 7 family fold. However, MglC has a distinct ∼30° to 40° shift in the orientation of the functionally important α2 helix compared with other structural homologs. Using isothermal titration calorimetry and size-exclusion chromatography, we show that MglC binds MglB in 2:4 stoichiometry with submicromolar range dissociation constant. Using small-angle X-ray scattering and molecular docking studies, we show that the MglBC complex consists of a MglC homodimer sandwiched between two homodimers of MglB. A combination of size-exclusion chromatography and site-directed mutagenesis studies confirmed the MglBC interacting interface obtained by molecular docking studies. Finally, we show that the C-terminal region of MglB, crucial for binding its established partner MglA, is not required for binding MglC. These studies suggest that the MglB uses distinct interfaces to bind MglA and MglC. Based on these data, we propose a model suggesting a new role for MglC in polarity reversal in M. xanthus. American Society for Biochemistry and Molecular Biology 2021-01-22 /pmc/articles/PMC7949163/ /pubmed/33493516 http://dx.doi.org/10.1016/j.jbc.2021.100308 Text en © 2021 The Authors https://creativecommons.org/licenses/by/4.0/This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).
spellingShingle Research Article
Kapoor, Srajan
Kodesia, Akriti
Kalidas, Nidhi
Ashish
Thakur, Krishan Gopal
Structural characterization of Myxococcus xanthus MglC, a component of the polarity control system, and its interactions with its paralog MglB
title Structural characterization of Myxococcus xanthus MglC, a component of the polarity control system, and its interactions with its paralog MglB
title_full Structural characterization of Myxococcus xanthus MglC, a component of the polarity control system, and its interactions with its paralog MglB
title_fullStr Structural characterization of Myxococcus xanthus MglC, a component of the polarity control system, and its interactions with its paralog MglB
title_full_unstemmed Structural characterization of Myxococcus xanthus MglC, a component of the polarity control system, and its interactions with its paralog MglB
title_short Structural characterization of Myxococcus xanthus MglC, a component of the polarity control system, and its interactions with its paralog MglB
title_sort structural characterization of myxococcus xanthus mglc, a component of the polarity control system, and its interactions with its paralog mglb
topic Research Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7949163/
https://www.ncbi.nlm.nih.gov/pubmed/33493516
http://dx.doi.org/10.1016/j.jbc.2021.100308
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