Escherichia coli K-12 substr. MG1655 Polypeptide: regulatory peptide whose translation enables hokC (gef) expression

Gene: mokC Accession Numbers: EG10373 (EcoCyc), b0018, ECK0018

Synonyms: gefL

Regulation Summary Diagram: ?

Regulation summary diagram for mokC

Sequence analysis indicates that the hokC gene is a homologue of the hok (host killing) gene which is responsible for mediating plasmid stabilization by post-segregational killing (PSK) in plasmid R1. hok encodes a stable mRNA whose translation is inhibited by a less stable mRNA encoded by sok. The stable mRNA from hokC encodes a polypeptide that induction experiments have shown to be toxic to Escherichia coli host cells, resulting in cell growth arrest, morphological changes, and rapid cell killing. The hokC system is inactive due to insertion of the insertion element IS186 22 bp downstream of the gene. Sequence analysis shows that after the removal of the IS186 element sequence, the hokC system contains regulatory elements described for the hok/sok system from plasmid R1 including a fold-back inhibition element (fbi), a translational activation element (tac), a promoter, and an overlapping open reading frame named mokC. Northern analysis using the hokC sysem from ECOR24 which does not contain the IS186 element has shown that the fbi sequence is exonucleolytically removed during post-transcriptional processing, and that the hokC locus also encodes a small, less stable antisense RNA complimentary to the hokC mRNA leader in the mokC open reading frame. The antisense RNA is homologous to Sok-RNA from plasmid R1, and is believed to be designed to regulate hokC translation by inhibiting translation of the overlapping mokC. It has been shown that hokC is unable to mediate PSK [Pedersen99].

Locations: membrane

Map Position: [16,751 <- 16,960] (0.36 centisomes, 1°)
Length: 210 bp / 69 aa

Molecular Weight of Polypeptide: 7.742 kD (from nucleotide sequence)

Unification Links: ASAP:ABE-0000064 , EchoBASE:EB1999 , EcoGene:EG12074 , EcoliWiki:b0018 , OU-Microarray:b0018 , PortEco:mokC , Protein Model Portal:P33236 , RefSeq:NP_414559 , RegulonDB:EG10373 , String:511145.b0018 , UniProt:P33236

Relationship Links: InterPro:IN-FAMILY:IPR000021 , InterPro:IN-FAMILY:IPR018084 , Pfam:IN-FAMILY:PF01848 , Prints:IN-FAMILY:PR00281 , ProDom:IN-FAMILY:PD005979 , Prosite:IN-FAMILY:PS00556

GO Terms:

Cellular Component: GO:0016020 - membrane Inferred by computational analysis [UniProtGOA11, UniProtGOA11a, GOA01]
GO:0016021 - integral component of membrane Inferred by computational analysis [UniProtGOA11a]

MultiFun Terms: cell processes protection cell killing

Sequence Features

Protein sequence of regulatory peptide whose translation enables hokC (gef) expression with features indicated

Feature Class Location Citations Comment
Transmembrane-Region 24 -> 44
UniProt: Helical;; Non-Experimental Qualifier: potential;

Gene Local Context (not to scale): ?

Gene local context diagram

Transcription Unit:

Transcription-unit diagram


Suzanne Paley on Thu Oct 21, 2004:
Position updated based on U00096.2 release of genome
10/20/97 Gene b0018 from Blattner lab Genbank (v. M52) entry merged into EcoCyc gene EG10373; confirmed by SwissProt match.


GOA01: GOA, DDB, FB, MGI, ZFIN (2001). "Gene Ontology annotation through association of InterPro records with GO terms."

Pedersen99: Pedersen K, Gerdes K (1999). "Multiple hok genes on the chromosome of Escherichia coli." Mol Microbiol 32(5);1090-102. PMID: 10361310

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

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 Tue Oct 13, 2015, biocyc13.