Cited by 27Bacterial Genetics and BiotechnologyDrug Transport and Resistance MechanismsBiochemical and Structural Characterization

The Two Distinct Types of SecA2-Dependent Export Systems

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Braunstein, Miriam, Bensing, Barbara A., Sullam, Paul M.·2019·Microbiology Spectrum

Abstract

In addition to SecA of the general Sec system, many Gram-positive bacteria, including mycobacteria, express SecA2, a second, transport-associated ATPase. SecA2s can be subdivided into two mechanistically distinct types: (i) SecA2s that are part of the accessory Sec (aSec) system, a specialized transporter mediating the export of a family of serine-rich repeat (SRR) glycoproteins that function as adhesins, and (ii) SecA2s that are part of multisubstrate systems, in which SecA2 interacts with components of the general Sec system, specifically the SecYEG channel, to export multiple types of substrates. Found mainly in streptococci and staphylococci, the aSec system also contains SecY2 and novel accessory Sec proteins (Asps) that are required for optimal export. Asp2 also acetylates glucosamine residues on the SRR domains of the substrate during transport. Targeting of the SRR substrate to SecA2 and the aSec translocon is mediated by a specialized signal peptide. Multisubstrate SecA2 systems are present in mycobacteria, corynebacteria, listeriae, clostridia, and some bacillus species. Although most substrates for this SecA2 have canonical signal peptides that are required for export, targeting to SecA2 appears to depend on structural features of the mature protein. The feature of the mature domains of these proteins that renders them dependent on SecA2 for export may be their potential to fold in the cytoplasm. The discovery of aSec and multisubstrate SecA2 systems expands our appreciation of the diversity of bacterial export pathways. Here we present our current understanding of the mechanisms of each of these SecA2 systems.

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Crossref · 10.1128/microbiolspec.psib-0025-2018

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  • SecA2 is found in all species of Mycobacterium, other Actinobacteria, and also in several Gram-positive pathogens.

    “SecA2 is found in all species of Mycobacterium, other Actinobacteria, and also in several Gram-positive pathogens (78, 79).”

    From Mycobacterium smegmatis: The Vanguard of Mycobacterial Research (2023) · cites this paper as [78]

    The Introduction’s “Multi-substrate SecA2 systems” section describes SecA2 systems in mycobacteria and Corynebacterium glutamicum, as well as Gram-positive pathogens including Listeria monocytogenes and Bacillus anthracis (page not available in our copy). It does not establish the claim’s stronger assertion that SecA2 occurs in every Mycobacterium species. (LLM, conf=0.86)

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Research works printed but not linked: 1

  1. [77]Archambaud C, Nahori MA, Pizarro-Cerda J, Cossart P, Dussurget O. 2006 Control of Listeria superoxide dismutase by phosphorylation. J Biol Chem 281: 31812– 31822. 16905535

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Authors
Braunstein, M., Bensing, B. A., & Sullam, P. M.
Affiliations
  • University of North Carolina at Chapel Hill (US)
  • San Francisco VA Medical Center (US)
Corresponding author
  • Braunstein, Miriam
  • Sullam, Paul M.
Venue
Microbiology Spectrum
Published
2019-05-31
Volume
7
Issue
3
ISSN
2165-0497 (ISSN-L)
OpenAlex
W2953360012
Cited by
27
References
91
Citations by year
2026: 8 · 2025: 7 · 2024: 4 · 2023: 5 · 2021: 1 · 2020: 2
FWCI
0.10
Type
journal article
Language
en
Open access
Locations
  • Microbiology Spectrum (publishedVersion)
  • PubMed Central (publishedVersion)
  • PubMed (publishedVersion)
  • eScholarship (California Digital Library) (submittedVersion)
Funders
  • National Institutes of Health
  • National Institute of Allergy and Infectious Diseases (R01AI054540, R01AI041513)
Topics
  • Life Sciences › Biochemistry, Genetics and Molecular Biology › Genetics › Bacterial Genetics and Biotechnology
  • Health Sciences › Medicine › Oncology › Drug Transport and Resistance Mechanisms
  • Life Sciences › Biochemistry, Genetics and Molecular Biology › Molecular Biology › Biochemical and Structural Characterization
Keywords
SecA2, SecA, SecYEG channel, adhesins, signal peptide, protein export, ATPase, Gram-positive bacteria, mycobacteria, Streptococcus, Staphylococcus, Corynebacterium, Clostridia, Bacillus
MeSH terms
Adenosine Triphosphatases, Bacteria, Bacterial Proteins, Gram-Positive Bacteria, Mycobacterium, Staphylococcus, Streptococcus, Adhesins, Bacterial, Membrane Transport Proteins

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