Evidence map›Paper›PMID 38358254›Full record

ArticleProtein science : a publication of the Protein Society2024

The C-terminus is essential for the stability of the mycobacterial channel protein MspA.

Mikhail Pavlenok, Rashmi Ravindran Nair, R Curtis Hendrickson, Michael Niederweis

Open access · hybridAbstract read
In one paragraph

Article in Protein science : a publication of the Protein Society, 2024. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 2 papers.

0numbers the graph read from it
0cells of the map it votes in
2citing papers in PubMed
1.9field-weighted citation impact, top 15% of its field
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

2 citing papers in PubMed, 5 citations in OpenAlex.

  1. Article
  2. The C-terminus is essential for the stability of the mycobacterial channel protein MspA.Protein science : a publication of the Protein Society · 2024
    Article
4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

4 authors at 1 institution in 1 country.

Mikhail PavlenokDepartment of Microbiology, University of Alabama at Birmingham, Birmingham, Alabama, USA.
Rashmi Ravindran NairDepartment of Microbiology, University of Alabama at Birmingham, Birmingham, Alabama, USA.
R Curtis HendricksonDepartment of Microbiology, University of Alabama at Birmingham, Birmingham, Alabama, USA.
Michael NiederweisDepartment of Microbiology, University of Alabama at Birmingham, Birmingham, Alabama, USA.ORCID 0000-0003-4068-8092
University of Alabama at Birmingham · US

Funding

Asymmetric Single-Chain MspA nanopores for electroosmotic stretching and sequencing proteinsR01HG012553 · NHGRI · NORTHEASTERN UNIVERSITY · PI AKSIMENTIEV, ALEKSEI, CHEN, MIN · 2023 to 2023
$2.0M
Single-chain MspA for nanopore sequencing of DNAR21HG010543 · NHGRI · UNIVERSITY OF ALABAMA AT BIRMINGHAM · PI NIEDERWEIS, MICHAEL · 2019 to 2020
$408k
NHGRI NIH HHS R01 HG012553NHGRI NIH HHS R21 HG010543NIH HHS R01 HG012553NIH HHS R21 HG010543
6 · The paper itself

Abstract

Outer membrane proteins perform essential functions in uptake and secretion processes in bacteria. MspA is an octameric channel protein in the outer membrane of Mycobacterium smegmatis and is structurally distinct from any other known outer membrane protein. MspA is the founding member of a family with more than 3000 homologs and is one of the most widely used proteins in nanotechnological applications due to its advantageous pore structure and extraordinary stability. While a conserved C-terminal signal sequence is essential for folding and protein assembly in the outer membrane of Gram-negative bacteria, the molecular determinants of these processes are unknown for MspA. In this study, we show that mutation and deletion of methionine 183 in the highly conserved C-terminus of MspA and mutation of the conserved tryptophan 40 lead to a complete loss of protein in heat extracts of M. smegmatis. Swapping these residues partially restores the heat stability of MspA indicating that methionine 183 and tryptophan 40 form a conserved sulfur-π electron interaction, which stabilizes the MspA monomer. Flow cytometry showed that all MspA mutants are surface-accessible demonstrating that oligomerization and membrane integration in M. smegmatis are not affected. Thus, the conserved C-terminus of MspA is essential for its thermal stability, but it is not required for protein assembly in its native membrane, indicating that this process is mediated by a mechanism distinct from that in Gram-negative bacteria. These findings will benefit the rational design of MspA-like pores to tailor their properties in current and future applications.

Indexed as

MycobacteriumTryptophanMethionineMycobacterium smegmatisPorinsMethioninePorinsTryptophanchannelelectrophysiologynanopore sequencingporinprotein stabilitystochastic sensing

Identifiers

PMID38358254
PMCPMC10868439
OpenAlexW4391843775

What OpenQuestion holds

Textmetadata
LicenceCC BY-NC-ND
Read underepoch 390

Registered trials

None linked

Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.