• Skip to primary navigation
  • Skip to main content
College of Agriculture & Life Sciences
Department of Biochemistry and Biophysics
  • Degrees and Programs
    • Undergraduate
      • B.S. Biochemistry
      • B.S. Genetics
      • Biochemistry and Genetics Undergraduate Minors
      • Departmental Honors Program in Biochemistry
      • Departmental Honors Program in Genetics
      • BICH/GENE 491 Research
      • Overrides, Force Requests, and Prerequisites
      • Undergraduate Biochemistry & Genetics Society (BGS)
      • REU Program
      • Undergraduate Academic Advising
    • Graduate
      • Ph.D. Biochemistry and Molecular Biophysics
      • Meetings and the Graduate Committees
      • Graduate Curriculum and Roadmap
      • After I Graduate
      • Biochemistry Graduate Association (BGA)
      • Graduate Advising
    • Student Life
  • Admissions and Aid
    • Undergraduate Student Admissions
    • Graduate Application Information
    • Scholarships and Financial Aid
      • Undergraduate Scholarships and Financial Aid
      • Graduate Funding
  • Research
    • Research Active Faculty
    • Collaborative Research Resources
    • Postdoctoral Research
  • Get Connected
    • Department News
    • Department Calendar
    • Department Climate Committee
    • Giving to Biochemistry and Biophysics
  • About
    • Academic Professional Faculty
    • Faculty
    • News and Media
    • Department Leadership
    • Department History
    • Employment Opportunities
    • Department Directory
    • Contact Us
  • Seminars
  • Stockroom
Search

← Return to the Department Directory | Return to All Research Active Faculty

Straight, Paul

Paul Straight

Associate Professor, Biochemistry and Biophysics, Genetics
Focus Area:  bacteria, microbiology, metabolism, antibiotics, signaling, microbial communities, secondary metabolites, bacillus subtilis, streptomyces, motility, bacterial genetics, mass spectrometry
Office:  
BICH 435A
Email:  
[email protected]
Phone:  
979-314-8293 Lab phone: 979-314-8298

Education

Undergraduate Education
B.S. Lewis & Clark College
Graduate Education
Ph.D. U. of Colorado, Boulder
Postdoc. Harvard Medical School

Areas of Expertise

  • Microbiology
  • Bacterial Genetics
  • Natural Products
  • Actinomycetes
  • Biofilms
  • Electron Microscopy

Professional Summary

The Straight lab studies chemical and genetic mechanisms of interaction between species of bacteria. Interspecies interactions are the foundation of the bacterial communities that shape the environment and human health. Recognizing the importance of these microorganisms in the biosphere, there remains much to learn about the mechanisms bacteria use to communicate and compete with each other. Using model systems—specifically, species of soil bacteria, Bacillus and Streptomyces—and several experimental approaches, we aim to discover new interaction mechanisms, which in turn reveal the remarkable abilities bacteria have to sense and respond to other species.

Bacteria mobilizing bacteria

A two-species interaction between bacteria.: Streptomyces venezuelae–six spots in a horizontal line and Bacillus subtilis–six spots on a vertical line. When close to S. venezuelae, the B. subtilis becomes mobile, spreading to form an X pattern.

A two-species interaction between bacteria.: Streptomyces venezuelae–six spots in a horizontal line and Bacillus subtilis–six spots on a vertical line. When close to S. venezuelae, the B. subtilis becomes mobile, spreading to form an X pattern. See mSphere 3 (2018).

Using different species of Streptomyces, we observe that B. subtilis often mobilizes a population of cells to expand across a surface of agar. We selected one species and identified the inducer as the classic antibiotic, chloramphenicol, from S. venezuelae. Using this model interaction, we found that B. subtilis has an early warning system for the detection of competitors. We are investigating the mechanism that enables B. subtilis to detect chloramphenicol and other inducers. We are also investigating how B. subtilis switches from normal growth to expansion of the population, which is a mechanism of survival when confronted with antibiotic-producing competitors. Finally, we are using mobilization as a bioassay to detect and identify new inducer metabolites from Streptomyces spp. We will determine how the new inducers function, and if new antibiotics are among them.

Y. Liu, S. Kyle, P. D. Straight, Antibiotic stimulation of a bacillus subtilis migratory response. mSphere 3 (2018).

The secondary metabolome of Streptomyces

Disruption of secondary metabolite synthesis generates phenotypes, which are observed using MALDI-mass spectrometry (left) and colony morphology (right). We use this approach to discover new metabolites for bacterial growth and competitive fitness. (Unpublished data.)

Disruption of secondary metabolite synthesis generates phenotypes, which are observed using MALDI-mass spectrometry (left) and colony morphology (right). We use this approach to discover new metabolites for bacterial growth and competitive fitness. (Unpublished data.)

Many species of bacteria produce bioactive metabolites that perform important functions in nature but are mysterious in laboratory cultures. Historically, the secondary metabolites of interest have been antibiotics. Thus, research in this field focuses primarily on antibiotic activities, leaving the majority of secondary metabolites with no known function. We are developing and using streamlined genetic approaches to disrupt the secondary metabolome of Streptomyces spp. in order to uncover new metabolites, their unknown functions, and the undiscovered antibiotics that may be hidden within secondary metabolome.

S. R. Barger, B. C. C. Hoefler, A. Cubillos-Ruiz, W. K. Russell, D. H. Russell, P. D. Straight, Imaging secondary metabolism of Streptomyces sp. Mg1 during cellular lysis and colony degradation of competing Bacillus subtilis. Anton. Leeuw. Int. J. G. 102, 435–445 (2012).

Biosynthetic Pipelines for Antibiotic Production by Bacteria

Biosynthetic pipelines for antibiotic production. A single species of bacteria may produce several different antibiotics. Their biosynthesis requires coordination of gene expression, enzyme assembly, central metabolism for precursors, and export machinery for delivery. We use combined approaches of light and electron microscopy with biochemical and genetic experiments to identify the elements of individual pipelines and their mechanisms of assembly in the bacterial cell.

One example of a biosynthetic pipeline is production of the antibiotic bacillaene by Bacillus subtilis. Bacillaene is synthesized by a megacomplex of enzymes. How these enzymes associate with the plasma membrane to export bacillaene is not known. We use genetic approaches to determine the cellular requirements for bacillaene export. A second example is the antibiotic family of linearmycins. We discovered that the linearmycins are packaged into extracellular vesicles by Streptomyces sp. Mg1. We are using this system to understand how the vesicles are produced, loaded with the linearmycins, and released across the cell envelope of these

Gram-positive bacteria. These studies will provide insights into the cellular constraints for antibiotic production that will facilitate bacterial engineering approaches to antibiotic discovery.

B. C. Hoefler, R. M. Stubbendieck, N. K. Josyula, S. M. Moisan, E. M. Schulze, P. D. Straight, A link between linearmycin biosynthesis and extracellular vesicle genesis connects specialized metabolism and bacterial membrane physiology. Cell Chem. Biol. 24, 1238–1249 (2017).

Metabolites and enzymes in competitive interactions

Linearmycins cause lysis of B. subtilis cells, but resistant cells emerge due to mutations that activate the LnrJK (YfiJK) two-component signaling system that controls an ABC transporter, LnrLMN (YfiLNM). LnrLMN provides linearmycin resistance and biofilm formation by an unknown mechanism.
See J. Bacteriol. 199 (2017).

Our studies using bacterial interactions are building a deeper understanding of bacterial competitive functions and fitness. Bacteria that produce bioactive metabolites may produce many of them at the same time. They may also produce and secrete enzymes that interact with metabolites of other organisms. These processes are integral to bacterial competition. Through in-depth studies of two species interactions, we are discovering layers of complexity in bacterial competition. Our data enables us to reconstruct elaborate views of the functions at work during competition, which we believe will better reflect the nature of bacterial interactions and community formation.

R. M. Stubbendieck and P. D. Straight, Escape from lethal bacterial competition through coupled activation of antibiotic resistance and a mobilized subpopulation. PLoS Genetics 11 (2015).

 

 

Publications

  • View publications on PubMed
A member of
Texas A&M AgriLife

Texas A&M AgriLife Extension Service | Texas A&M AgriLife Research | Texas A&M Forest Service | Texas A&M Veterinary Medical Diagnostic Lab | College of Agriculture & Life Sciences

Department Quick Links

  • About
  • AgriLife Intranet
  • Degrees and Programs
  • Employment Opportunities
  • Contact Us
300 Olsen Blvd. College Station, Tx 77843-2128
(979) 845-5032
Department of Biochemistry and Biophysics

© 2025 Texas A&M University. All rights reserved.

  • Compact with Texans
  • Privacy and Security
  • Accessibility Policy
  • State Link Policy
  • Statewide Search
  • Veterans Benefits
  • Military Families
  • Risk, Fraud & Misconduct Hotline
  • Texas Homeland Security
  • Texas Veterans Portal
  • Equal Opportunity
  • Open Records/Public Information