Escherichia coli K-12 substr. MG1655 Polypeptide: secretion monitor that regulates SecA translation (General Secretory Pathway)

Gene: secM Accession Numbers: EG11087 (EcoCyc), b0097, ECK0098

Synonyms: srrA, yacA

Regulation Summary Diagram: ?

Regulation summary diagram for secM

SecM regulates production of co-translated SecA; reduced secretion of SecM acts as a "sensor" that stimulates translation of the SecA translocation factor [Oliver98] via a translational pause at Pro166 that is caused by an arrest sequence that interacts with the ribosomal exit tunnel [Nakatogawa01, Nakatogawa02, Sarker02, Butkus03, Murakami04]. The pause results in a translationally permissive mRNA secondary structure in the SecA region of the transcript [Nakatogawa01].

SecM has an unusual [Sarker00] cleavable signal sequence [Rajapandi91], mutations in which compromise the mechanism of SecA regulation by cellular secretion status [Oliver98, Sarker02]. SecM is subject to periplasmic proteolysis [Nakatogawa01].

SecM is not essential; a secM mutant exhibits growth and protein export [Rajapandi91]. However, a secM166 mutant is is arrest-defective and lethal unless SecA is provided on a plasmid [Murakami04]. The am109 mutation in secM causes polar effects on secA that result in amber-suppressable lethality [Schmidt88a]. Mutations result in periplasmic protein translocation defects [Tian02].

Regulation has been described [Schmidt88a, Schmidt89].

SecM = "secretion monitor"

Reviews: [Nakatogawa04, Nakatogawa04a]

Citations: [Fikes89, Fortin90, Schmidt91, Schmidt01, Serres01, VazquezLaslop11]

Gene Citations: [Schmidt91]

Locations: periplasmic space, cytosol

Map Position: [107,705 -> 108,217] (2.32 centisomes, 8°)
Length: 513 bp / 170 aa

Molecular Weight of Polypeptide: 18.88 kD (from nucleotide sequence)

Unification Links: ASAP:ABE-0000340 , EchoBASE:EB1079 , EcoGene:EG11087 , EcoliWiki:b0097 , OU-Microarray:b0097 , PortEco:secM , PR:PRO_000023929 , Pride:P62395 , Protein Model Portal:P62395 , RefSeq:NP_414639 , RegulonDB:EG11087 , String:511145.b0097 , UniProt:P62395

Relationship Links: InterPro:IN-FAMILY:IPR009502 , Pfam:IN-FAMILY:PF06558 , ProDom:IN-FAMILY:PD089227

GO Terms:

Biological Process: GO:0006417 - regulation of translation Inferred from experiment [Oliver98]
Molecular Function: GO:0045182 - translation regulator activity Inferred from experiment Inferred by computational analysis [GOA01a, Nakatogawa01]
Cellular Component: GO:0042597 - periplasmic space Inferred from experiment Inferred by computational analysis [UniProtGOA11, UniProtGOA11a, Nakatogawa01]
GO:0005737 - cytoplasm Inferred by computational analysis [UniProtGOA11a]
GO:0005829 - cytosol Inferred by computational analysis [UniProtGOA11, GOA06]
GO:0030288 - outer membrane-bounded periplasmic space Inferred by computational analysis [DiazMejia09]

MultiFun Terms: information transfer protein related export, signal peptide cleavage
information transfer protein related translation
regulation type of regulation posttranscriptional translation attenuation and efficiency

Essentiality data for secM knockouts: ?

Growth Medium Growth? T (°C) O2 pH Osm/L Growth Observations
LB Lennox No 37 Aerobic 7   No [Baba06, Comment 1]

Sequence Features

Protein sequence of secretion monitor that regulates SecA translation (General Secretory Pathway) with features indicated

Feature Class Location Citations Comment
Mutagenesis-Variant 1
[Sarker00, UniProt15]
UniProt: Protein is not produced, (and therefore neither is SecA) indicating this is the start codon.
Signal-Sequence 1 -> 37
UniProt: Non-Experimental Qualifier: potential;
Mutagenesis-Variant 24
[Sarker02, UniProt15]
UniProt: Protein is produced; this is not the start codon.
Mutagenesis-Variant 29 -> 33
[Oliver98, UniProt15]
UniProt: Loss of the ability to repress SecA-LacZ fusion proteins, translational pausing is very long, with almost no secretion.
Mutagenesis-Variant 31 -> 34
[Oliver98, UniProt15]
UniProt: Loss of the ability to repress SecA-LacZ fusion proteins.
Chain 38 -> 170
UniProt: Secretion monitor;
Mutagenesis-Variant 163
[Sarker00, UniProt15]
UniProt: Abolishes translation arrest.
Mutagenesis-Variant 166
[Sarker00, UniProt15]
P → A or missing: Abolishes translation arrest.

Gene Local Context (not to scale): ?

Gene local context diagram

Transcription Unit:

Transcription-unit diagram


Peter D. Karp on Wed Jan 18, 2006:
Gene left-end position adjusted based on analysis performed in the 2005 E. coli annotation update [Riley06 ].
Peter D. Karp on Thu Jan 16, 2003:
Predicted gene function revised as a result of E. coli genome reannotation by Serres et al. [Serres01 ].
10/20/97 Gene b0097 from Blattner lab Genbank (v. M52) entry merged into EcoCyc gene EG11087; confirmed by SwissProt match.


Baba06: Baba T, Ara T, Hasegawa M, Takai Y, Okumura Y, Baba M, Datsenko KA, Tomita M, Wanner BL, Mori H (2006). "Construction of Escherichia coli K-12 in-frame, single-gene knockout mutants: the Keio collection." Mol Syst Biol 2;2006.0008. PMID: 16738554

Butkus03: Butkus ME, Prundeanu LB, Oliver DB (2003). "Translocon "pulling" of nascent SecM controls the duration of its translational pause and secretion-responsive secA regulation." J Bacteriol 185(22);6719-22. PMID: 14594848

DiazMejia09: Diaz-Mejia JJ, Babu M, Emili A (2009). "Computational and experimental approaches to chart the Escherichia coli cell-envelope-associated proteome and interactome." FEMS Microbiol Rev 33(1);66-97. PMID: 19054114

Fikes89: Fikes JD, Bassford PJ (1989). "Novel secA alleles improve export of maltose-binding protein synthesized with a defective signal peptide." J Bacteriol 171(1);402-9. PMID: 2536662

Fortin90: Fortin Y, Phoenix P, Drapeau GR (1990). "Mutations conferring resistance to azide in Escherichia coli occur primarily in the secA gene." J Bacteriol 172(11);6607-10. PMID: 2146254

GOA01a: GOA, DDB, FB, MGI, ZFIN (2001). "Gene Ontology annotation through association of InterPro records with GO terms."

GOA06: GOA, SIB (2006). "Electronic Gene Ontology annotations created by transferring manual GO annotations between orthologous microbial proteins."

Murakami04: Murakami A, Nakatogawa H, Ito K (2004). "Translation arrest of SecM is essential for the basal and regulated expression of SecA." Proc Natl Acad Sci U S A 101(33);12330-5. PMID: 15302932

Nakatogawa01: Nakatogawa H, Ito K (2001). "Secretion monitor, SecM, undergoes self-translation arrest in the cytosol." Mol Cell 7(1);185-92. PMID: 11172723

Nakatogawa02: Nakatogawa H, Ito K (2002). "The ribosomal exit tunnel functions as a discriminating gate." Cell 108(5);629-36. PMID: 11893334

Nakatogawa04: Nakatogawa H, Ito K (2004). "Intraribosomal regulation of expression and fate of proteins." Chembiochem 5(1);48-51. PMID: 14695511

Nakatogawa04a: Nakatogawa H, Murakami A, Ito K (2004). "Control of SecA and SecM translation by protein secretion." Curr Opin Microbiol 7(2);145-50. PMID: 15063851

Oliver98: Oliver D, Norman J, Sarker S (1998). "Regulation of Escherichia coli secA by cellular protein secretion proficiency requires an intact gene X signal sequence and an active translocon." J Bacteriol 180(19);5240-2. PMID: 9748461

Rajapandi91: Rajapandi T, Dolan KM, Oliver DB (1991). "The first gene in the Escherichia coli secA operon, gene X, encodes a nonessential secretory protein." J Bacteriol 173(22);7092-7. PMID: 1834634

Riley06: Riley M, Abe T, Arnaud MB, Berlyn MK, Blattner FR, Chaudhuri RR, Glasner JD, Horiuchi T, Keseler IM, Kosuge T, Mori H, Perna NT, Plunkett G, Rudd KE, Serres MH, Thomas GH, Thomson NR, Wishart D, Wanner BL (2006). "Escherichia coli K-12: a cooperatively developed annotation snapshot--2005." Nucleic Acids Res 34(1);1-9. PMID: 16397293

Sarker00: Sarker S, Rudd KE, Oliver D (2000). "Revised translation start site for secM defines an atypical signal peptide that regulates Escherichia coli secA expression." J Bacteriol 182(19);5592-5. PMID: 10986266

Sarker02: Sarker S, Oliver D (2002). "Critical regions of secM that control its translation and secretion and promote secretion-specific secA regulation." J Bacteriol 184(9);2360-9. PMID: 11948148

Schmidt01: Schmidt MO, Brosh RM, Oliver DB (2001). "Escherichia coli SecA helicase activity is not required in vivo for efficient protein translocation or autogenous regulation." J Biol Chem 276(40);37076-85. PMID: 11477104

Schmidt88a: Schmidt MG, Rollo EE, Grodberg J, Oliver DB (1988). "Nucleotide sequence of the secA gene and secA(Ts) mutations preventing protein export in Escherichia coli." J Bacteriol 170(8);3404-14. PMID: 2841285

Schmidt89: Schmidt MG, Oliver DB (1989). "SecA protein autogenously represses its own translation during normal protein secretion in Escherichia coli." J Bacteriol 171(2);643-9. PMID: 2464580

Schmidt91: Schmidt MG, Dolan KM, Oliver DB (1991). "Regulation of Escherichia coli secA mRNA translation by a secretion-responsive element." J Bacteriol 173(20);6605-11. PMID: 1833384

Serres01: Serres MH, Gopal S, Nahum LA, Liang P, Gaasterland T, Riley M (2001). "A functional update of the Escherichia coli K-12 genome." Genome Biol 2(9);RESEARCH0035. PMID: 11574054

Tian02: Tian H, Beckwith J (2002). "Genetic screen yields mutations in genes encoding all known components of the Escherichia coli signal recognition particle pathway." J Bacteriol 184(1);111-8. PMID: 11741850

UniProt09: UniProt Consortium (2009). "UniProt version 15.8 released on 2009-10-01 00:00:00." Database.

UniProt10: UniProt Consortium (2010). "UniProt version 2010-07 released on 2010-06-15 00:00:00." Database.

UniProt15: UniProt Consortium (2015). "UniProt version 2015-01 released on 2015-01-16 00:00:00." Database.

UniProtGOA11: UniProt-GOA (2011). "Gene Ontology annotation based on the manual assignment of UniProtKB Subcellular Location terms in UniProtKB/Swiss-Prot entries."

UniProtGOA11a: UniProt-GOA (2011). "Gene Ontology annotation based on manual assignment of UniProtKB keywords in UniProtKB/Swiss-Prot entries."

VazquezLaslop11: Vazquez-Laslop N, Mankin AS (2011). "Picky nascent peptides do not talk to foreign ribosomes." Proc Natl Acad Sci U S A 108(15);5931-2. PMID: 21464303

Report Errors or Provide Feedback
Please cite the following article in publications resulting from the use of EcoCyc: Nucleic Acids Research 41:D605-12 2013
Page generated by SRI International Pathway Tools version 19.0 on Mon Oct 5, 2015, biocyc13.