Molecular analysis of an operon in Bacillus subtilis encoding a novel ABC transporter with a role in exoprotein production, sporulation and competence

The compatible solute ABC (ATP-binding cassette) transporters are indispensable for acquiring a variety of compatible solutes under osmotic stress in Bacillus subtilis. The substrate-binding protein OpuCC (Opu is osmoprotectant uptake) of the ABC transporter OpuC can recognize a broad spectrum of compatible solutes, compared with its 70% sequence-identical paralogue OpuBC that can solely bind choline. To explore the structural basis of this difference of substrate specificity, we determined crystal structures of OpuCC in the apo-form and in complex with carnitine, glycine betaine, choline and ectoine respectively. OpuCC is composed of two α/β/α globular sandwich domains linked by two hinge regions, with a substrate-binding pocket located at the interdomain cleft. Upon substrate binding, the two domains shift towards each other to trap the substrate. Comparative structural analysis revealed a plastic pocket that fits various compatible solutes, which attributes the multiple-substrate binding property to OpuCC. This plasticity is a gain-of-function via a single-residue mutation of Thr94 in OpuCC compared with Asp96 in OpuBC.

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“Molecular Analysis of Some Genes from Plasmid p19 of the Bacillus subtilis 19 Soil Strain Involved in Conjugation”

Russian Journal of Genetics ◽

10.1134/s1022795408100177 ◽

2008 ◽

Vol 44 (10) ◽

pp. 1249-1249

Author(s):

E. U. Poluektova ◽

E. Yu. Gagarina ◽

I. P. Shilovskii ◽

E. A. Fedorina ◽

V. Z. Nezametdinova ◽

...

Keyword(s):

Bacillus Subtilis ◽

Molecular Analysis ◽

Soil Strain

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Lr34 multi-pathogen resistance ABC transporter: molecular analysis of homoeologous and orthologous genes in hexaploid wheat and other grass species

The Plant Journal ◽

10.1111/j.1365-313x.2010.04430.x ◽

2010 ◽

Vol 65 (3) ◽

pp. 392-403 ◽

Cited By ~ 57

Author(s):

Simon G. Krattinger ◽

Evans S. Lagudah ◽

Thomas Wicker ◽

Joanna M. Risk ◽

Anthony R. Ashton ◽

...

Keyword(s):

Molecular Analysis ◽

Abc Transporter ◽

Hexaploid Wheat ◽

Pathogen Resistance ◽

Grass Species ◽

Orthologous Genes

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Conformation control of the histidine kinase BceS of Bacillus subtilis by its cognate ABC-transporter facilitates need-based activation of antibiotic resistance

10.1101/2020.02.28.969956 ◽

2020 ◽

Cited By ~ 1

Author(s):

Alan Koh ◽

Marjorie J. Gibbon ◽

Marc W. Van der Kamp ◽

Christopher R. Pudney ◽

Susanne Gebhard

Keyword(s):

Gene Expression ◽

Antibiotic Resistance ◽

Bacillus Subtilis ◽

Abc Transporter ◽

Histidine Kinase ◽

Regulatory System ◽

Cost Effective ◽

Catalytic Core ◽

Complete Control ◽

Transport Flux

SUMMARYBacteria closely control gene expression to ensure optimal physiological responses to their environment. Such careful gene expression can minimize the fitness cost associated with antibiotic resistance. We previously described a novel regulatory logic in Bacillus subtilis enabling the cell to directly monitor its need for detoxification. This cost-effective strategy is achieved via a two-component regulatory system (BceRS) working in a sensory complex with an ABC-transporter (BceAB), together acting as a flux-sensor where signaling is proportional to transport activity. How this is realized at the molecular level has remained unknown. Using experimentation and computation we here show that the histidine kinase is activated by piston-like displacements in the membrane, which are converted to helical rotations in the catalytic core via an intervening HAMP-like domain. Intriguingly, the transporter was not only required for kinase activation, but also to actively maintain the kinase in its inactive state in the absence of antibiotics. Such coupling of kinase activity to that of the transporter ensures the complete control required for transport flux-dependent signaling. Moreover, we show that the transporter likely conserves energy by signaling with sub-maximal sensitivity. These results provide the first mechanistic insights into transport flux-dependent signaling, a unique strategy for energy-efficient decision making.

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Myristic Acid Inhibits the Activity of the Bacterial ABC Transporter BmrA

International Journal of Molecular Sciences ◽

10.3390/ijms222413565 ◽

2021 ◽

Vol 22 (24) ◽

pp. 13565

Author(s):

Kristin Oepen ◽

Hüseyin Özbek ◽

Anja Schüffler ◽

Johannes C. Liermann ◽

Eckhard Thines ◽

...

Keyword(s):

Bacillus Subtilis ◽

Fatty Acid ◽

Abc Transporter ◽

Abc Transporters ◽

Concentration Gradient ◽

Myristic Acid ◽

Inhibitory Effect ◽

Atp Binding ◽

Bacterial Cells ◽

Transport Activity

ATP-binding cassette (ABC) transporters are conserved in all kingdoms of life, where they transport substrates against a concentration gradient across membranes. Some ABC transporters are known to cause multidrug resistances in humans and are able to transport chemotherapeutics across cellular membranes. Similarly, BmrA, the ABC transporter of Bacillus subtilis, is involved in excretion of certain antibiotics out of bacterial cells. Screening of extract libraries isolated from fungi revealed that the C14 fatty acid myristic acid has an inhibitory effect on the BmrA ATPase as well as the transport activity. Thus, a natural membrane constituent inhibits the BmrA activity, a finding with physiological consequences as to the activity and regulation of ABC transporter activities in biological membranes.

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