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Escherichia coli K-12 substr. MG1655 Protein: MukF dimer

Gene: mukF Accession Numbers: EG12165 (EcoCyc), b0922, ECK0913

Synonyms: kicB

Regulation Summary Diagram

Regulation summary diagram for mukF

Component of:
MukEF complex (summary available)
bacterial condensin MukBEF (extended summary available)

Subunit composition of MukF dimer = [MukF]2
         Ca2+-binding protein involved in chromosome partitioning = MukF

MukF plays a role in chromosome partitioning during cell division [Yamanaka96]. The effect of MukF on chromosome partitioning may be due to a role in DNA topology or condensation [Sawitzke00]. MukF and MukE are proposed to be a toxin-antitoxin pair, respectively [Feng94].

A mukF mutant is viable [Feng94]. A mukF mutant is reported to exhibit heat sensitivity and formation of anucleate products of cell division [Yamanaka96]. A mukF mutant also exhibits increased sensitivity to novobiocin, compared to wild type [Onogi00]. A mukF mutant exhibits a defect in wild-type localization of MukB to nucleoid-associated foci [Ohsumi01]. Like a mukF mutation, MukF overproduction results in a cell division defect with anucleate cells [Yamanaka96]. A mukF mutation suppresses the viability defect of a mukE mutant [Feng94]. The heat sensitivity and division defects of a mukF mutant are suppressed by a topA10 or topA66 mutation, and this suppression is DNA gyrase dependent [Sawitzke00]. The heat sensitivity of a mukF mutant is partly suppressed by a dam or seqA mutation, whereas the novobiocin and anucleate cell phenotypes are not [Onogi00].

MukF has a leucine zipper region and an acidic region; both regions are functionally important [Yamanaka96]. MukF binds Ca2+ [Yamazoe99].

MukB, MukE and MukF form a complex; MukE binding to MukB requires MukF, whereas MukF binding to MukB does not require MukE, and complex formation is stimulated by Ca2+ or Mg2+ [Yamazoe99].

KicB: "killing of cell" [Feng94].

Regulation has been described [Feng94, Yamanaka95].

Locations: cytosol, bacterial nucleoid

Map Position: [973,542 -> 974,864] (20.98 centisomes, 76°)
Length: 1323 bp / 440 aa

Molecular Weight of Polypeptide: 50.579 kD (from nucleotide sequence)

Molecular Weight of Multimer: 105.0 kD (experimental) [Gloyd07]

Unification Links: ASAP:ABE-0003134, CGSC:31748, DIP:DIP-39981N, EchoBASE:EB2084, EcoGene:EG12165, EcoliWiki:b0922, Mint:MINT-1300138, OU-Microarray:b0922, PortEco:mukF, PR:PRO_000023311, Pride:P60293, Protein Model Portal:P60293, RefSeq:NP_415442, RegulonDB:EG12165, SMR:P60293, String:511145.b0922, UniProt:P60293

Relationship Links: InterPro:IN-FAMILY:IPR005582, InterPro:IN-FAMILY:IPR011991, PDB:Structure:1T98, PDB:Structure:3EUH, PDB:Structure:3RPU, Pfam:IN-FAMILY:PF03882

Gene-Reaction Schematic

Gene-Reaction Schematic

Genetic Regulation Schematic

Genetic regulation schematic for mukF

GO Terms:
Biological Process:
Inferred by computational analysisGO:0006260 - DNA replication [GOA06, GOA01a]
Inferred by computational analysisGO:0007049 - cell cycle [UniProtGOA11a]
Inferred by computational analysisGO:0007059 - chromosome segregation [UniProtGOA11a, GOA06, GOA01a]
Inferred by computational analysisGO:0030261 - chromosome condensation [UniProtGOA11a]
Inferred by computational analysisGO:0051301 - cell division [UniProtGOA11a]
Molecular Function:
Inferred from experimentGO:0005515 - protein binding [Woo09, Butland05, Oishi06]
Inferred by computational analysisGO:0005509 - calcium ion binding [GOA06, GOA01a]
Cellular Component:
Inferred by computational analysisGO:0005737 - cytoplasm [UniProtGOA11a, GOA06, GOA01a]
Inferred by computational analysisGO:0005829 - cytosol [DiazMejia09]
Inferred by computational analysisGO:0009295 - nucleoid [UniProtGOA11]

MultiFun Terms: cell processescell division
cell processesprotectioncell killing
information transferDNA related

Essentiality data for mukF knockouts:

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

Created 22-May-2008 by Keseler I, SRI International

Subunit of: MukEF complex

Subunit composition of MukEF complex = [MukE]4[(MukF)2]
         protein involved in chromosome partitioning = MukE (extended summary available)
         MukF dimer = (MukF)2
                 Ca2+-binding protein involved in chromosome partitioning = MukF

Component of: bacterial condensin MukBEF (extended summary available)

The MukEF complex is asymmetric and likely has an elongated shape [Petrushenko06]. An intermediate complex with 2:2 stiochiometry of MukE and MukF has also been observed; in vivo experiments suggest the presence of nearly equimolar amounts of F2E2 and F2E4 [Gloyd07].

Molecular Weight: 230.0 kD (experimental) [Petrushenko06]

Created 22-May-2008 by Keseler I, SRI International

Subunit of: bacterial condensin MukBEF

Inferred from experiment

Subunit composition of bacterial condensin MukBEF = [(MukB)2][(MukE)4([MukF]2)]
         cell division protein involved in chromosome partitioning = (MukB)2
                 cell division protein involved in chromosome partitioning = MukB
         MukEF complex = (MukE)4([MukF]2) (summary available)
                 protein involved in chromosome partitioning = MukE (extended summary available)
                 MukF dimer = (MukF)2
                         Ca2+-binding protein involved in chromosome partitioning = MukF

Two conformations of the MukBEF complex appear to exist; the half-saturated complex, with a stoichiometry of B2(E2F)1, is relatively stable and can bind DNA, while the fully saturated MukBEF complex, with a stoichiometry of B2(E2F)2, is short-lived, unable to bind DNA and able to form multimeric complexes [Petrushenko06].

The MukEF complex appears to compete with DNA for binding to MukB. The fully assembled MukBEF complex is unable to bind DNA; addition of MukEF to DNA-bound MukB displaces MukB from the DNA [Petrushenko06].

Electron microscopy studies indicated that the MukE and MukF subunits of the MukBEF complex associate with the terminal globular domains of the MukB homodimer. The MukBEF complex can also be observed to form multimeric complexes in a variety of conformations [Matoba05].

It was reported that he MukBEF complex can be detected in vitro only under conditions of increased Ca2+ or Mg2+ concentration [Yamazoe99]; however, [Matoba05] was able to purify the complex in the absence of ions.

A report that the MukBEF complex was able to compact a DNA molecule in an ATP binding-dependent manner [Case04] was later retracted [Case05].

Review: [Carter12]

Sequence Features

Protein sequence of Ca2+-binding protein involved in chromosome partitioning with features indicated

Feature Class Location Citations Comment
Pfam PF03882 3 -> 440
Inferred by computational analysis[Finn14]
KicB : KicB killing factor
Protein-Segment 208 -> 236
Author statement[UniProt15]
UniProt: Leucine-zipper; Sequence Annotation Type: region of interest.
Mutagenesis-Variant 233
Inferred from experiment[Yamanaka96]
UniProt: Abolishes function.
Protein-Segment 325 -> 356
Author statement[UniProt15]
UniProt: Asp/Glu-rich (acidic); Sequence Annotation Type: compositionally biased region.

Gene Local Context (not to scale -- see Genome Browser for correct scale)

Gene local context diagram

Transcription Unit

Transcription-unit diagram


10/20/97 Gene b0922 from Blattner lab Genbank (v. M52) entry merged into EcoCyc gene EG12165; 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

Butland05: Butland G, Peregrin-Alvarez JM, Li J, Yang W, Yang X, Canadien V, Starostine A, Richards D, Beattie B, Krogan N, Davey M, Parkinson J, Greenblatt J, Emili A (2005). "Interaction network containing conserved and essential protein complexes in Escherichia coli." Nature 433(7025);531-7. PMID: 15690043

Carter12: Carter SD, Sjogren C (2012). "The SMC complexes, DNA and chromosome topology: right or knot?." Crit Rev Biochem Mol Biol 47(1);1-16. PMID: 21923481

Case04: Case RB, Chang YP, Smith SB, Gore J, Cozzarelli NR, Bustamante C (2004). "The bacterial condensin MukBEF compacts DNA into a repetitive, stable structure." Science 305(5681);222-7. PMID: 15178751

Case05: Case RB, Chang YP, Smith SB, Gore J, Cozzarelli NR, Bustamante C (2005). "Retraction." Science 307(5714);1409. PMID: 15746408

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

Feng94: Feng J, Yamanaka K, Niki H, Ogura T, Hiraga S (1994). "New killing system controlled by two genes located immediately upstream of the mukB gene in Escherichia coli." Mol Gen Genet 243(2);136-47. PMID: 7513784

Finn14: Finn RD, Bateman A, Clements J, Coggill P, Eberhardt RY, Eddy SR, Heger A, Hetherington K, Holm L, Mistry J, Sonnhammer EL, Tate J, Punta M (2014). "Pfam: the protein families database." Nucleic Acids Res 42(Database issue);D222-30. PMID: 24288371

Gloyd07: Gloyd M, Ghirlando R, Matthews LA, Guarne A (2007). "MukE and MukF form two distinct high affinity complexes." J Biol Chem 282(19);14373-8. PMID: 17355972

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."

Matoba05: Matoba K, Yamazoe M, Mayanagi K, Morikawa K, Hiraga S (2005). "Comparison of MukB homodimer versus MukBEF complex molecular architectures by electron microscopy reveals a higher-order multimerization." Biochem Biophys Res Commun 333(3);694-702. PMID: 15979051

Ohsumi01: Ohsumi K, Yamazoe M, Hiraga S (2001). "Different localization of SeqA-bound nascent DNA clusters and MukF-MukE-MukB complex in Escherichia coli cells." Mol Microbiol 40(4);835-45. PMID: 11401691

Oishi06: Oishi Y, Yunomura S, Kawahashi Y, Doi N, Takashima H, Baba T, Mori H, Yanagawa H (2006). "Escherichia coli proteome chips for detecting protein-protein interactions." Proteomics 6(24);6433-6. PMID: 17109382

Onogi00: Onogi T, Yamazoe M, Ichinose C, Niki H, Hiraga S (2000). "Null mutation of the dam or seqA gene suppresses temperature-sensitive lethality but not hypersensitivity to novobiocin of muk null mutants." J Bacteriol 182(20);5898-901. PMID: 11004192

Petrushenko06: Petrushenko ZM, Lai CH, Rybenkov VV (2006). "Antagonistic interactions of kleisins and DNA with bacterial Condensin MukB." J Biol Chem 281(45);34208-17. PMID: 16982609

Sawitzke00: Sawitzke JA, Austin S (2000). "Suppression of chromosome segregation defects of Escherichia coli muk mutants by mutations in topoisomerase I." Proc Natl Acad Sci U S A 97(4);1671-6. PMID: 10660686

UniProt15: UniProt Consortium (2015). "UniProt version 2015-08 released on 2015-07-22." 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."

Woo09: Woo JS, Lim JH, Shin HC, Suh MK, Ku B, Lee KH, Joo K, Robinson H, Lee J, Park SY, Ha NC, Oh BH (2009). "Structural studies of a bacterial condensin complex reveal ATP-dependent disruption of intersubunit interactions." Cell 136(1);85-96. PMID: 19135891

Yamanaka95: Yamanaka K, Ogura T, Niki H, Hiraga S (1995). "Characterization of the smtA gene encoding an S-adenosylmethionine-dependent methyltransferase of Escherichia coli." FEMS Microbiol Lett 1995;133(1-2);59-63. PMID: 8566713

Yamanaka96: Yamanaka K, Ogura T, Niki H, Hiraga S (1996). "Identification of two new genes, mukE and mukF, involved in chromosome partitioning in Escherichia coli." Mol Gen Genet 1996;250(3);241-51. PMID: 8602138

Yamazoe99: Yamazoe M, Onogi T, Sunako Y, Niki H, Yamanaka K, Ichimura T, Hiraga S (1999). "Complex formation of MukB, MukE and MukF proteins involved in chromosome partitioning in Escherichia coli." EMBO J 18(21);5873-84. PMID: 10545099

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Please cite the following article in publications resulting from the use of EcoCyc: Nucleic Acids Research 41:D605-12 2013
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