|Gene:||mokC||Accession Numbers: EG10373 (EcoCyc), b0018, ECK0018|
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].
|Map Position: [16,751 <- 16,960] (0.36 centisomes)||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
|Cellular Component:||GO:0016020 - membrane
[UniProtGOA11a, UniProtGOA11, GOA01]
GO:0016021 - integral component of membrane [UniProtGOA11]
|MultiFun Terms:||cell processes → protection → cell killing|
|Transmembrane-Region||24 -> 44|
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.
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