Skip Header

You are using a version of browser that may not display all the features of this website. Please consider upgrading your browser.
Protein

Lon protease

Gene

lon

Organism
Escherichia coli (strain K12)
Status
Reviewed-Annotation score: -Experimental evidence at protein leveli

Functioni

ATP-dependent serine protease that mediates the selective degradation of mutant and abnormal proteins as well as certain short-lived regulatory proteins, including some antitoxins. Required for cellular homeostasis and for survival from DNA damage and developmental changes induced by stress. Degrades polypeptides processively to yield small peptide fragments that are 5 to 10 amino acids long. Binds to DNA in a double-stranded, site-specific manner. Endogenous substrates include the regulatory proteins RcsA and SulA, the transcriptional activator SoxS, UmuD and at least type II antitoxins CcdA, HipB and MazE (PubMed:8022284, PubMed:16460757, PubMed:22720069, PubMed:24375411). Its overproduction specifically inhibits translation through at least two different pathways, one of them being the YoeB-YefM toxin-antitoxin system (PubMed:15009896). Overproduction leads to very high persister cell formation (cells highly resistant to antibiotics), but not when 10 mRNA interferases are deleted, nor when Lon catalytic residues are mutated (PubMed:21788497).9 Publications

Miscellaneous

Both its proteolytic and protein-activated ATPase activities are stimulated by DNA, especially single-stranded DNA.
Both high- and low-affinity ATPase sites are present in the homooligomer. Optimal peptidase activity requires ATP binding and hydrolysis at both sites, but ATP hydrolysis is not stoichiometrically linked to peptide hydrolysis.

Catalytic activityi

Hydrolysis of proteins in presence of ATP.UniRule annotation

Activity regulationi

Contains an allosteric site (distinct from its active site), whose occupancy by an unfolded polypeptide leads to enzyme activation.

Kineticsi

  1. KM=0.201 mM for ATP for ATPase activity1 Publication

    Sites

    Feature keyPosition(s)DescriptionActionsGraphical viewLength
    Active sitei6791
    Active sitei722UniRule annotation1 Publication1

    Regions

    Feature keyPosition(s)DescriptionActionsGraphical viewLength
    Nucleotide bindingi356 – 363ATPUniRule annotation8

    GO - Molecular functioni

    • ATPase activity Source: EcoliWiki
    • ATP binding Source: EcoCyc
    • ATP-dependent peptidase activity Source: EcoliWiki
    • DNA binding Source: EcoliWiki
    • peptidase activity Source: EcoliWiki
    • sequence-specific DNA binding Source: UniProtKB-UniRule
    • serine-type endopeptidase activity Source: EcoliWiki

    GO - Biological processi

    Keywordsi

    Molecular functionHydrolase, Protease, Serine protease
    Biological processStress response
    LigandATP-binding, Nucleotide-binding

    Enzyme and pathway databases

    BioCyciEcoCyc:EG10542-MONOMER
    MetaCyc:EG10542-MONOMER
    BRENDAi3.4.21.53 2026

    Protein family/group databases

    MEROPSiS16.001

    Names & Taxonomyi

    Protein namesi
    Recommended name:
    Lon proteaseUniRule annotation (EC:3.4.21.53UniRule annotation)
    Alternative name(s):
    ATP-dependent protease LaUniRule annotation
    Gene namesi
    Name:lonUniRule annotation
    Synonyms:capR, deg, lopA, muc
    Ordered Locus Names:b0439, JW0429
    OrganismiEscherichia coli (strain K12)
    Taxonomic identifieri83333 [NCBI]
    Taxonomic lineageiBacteriaProteobacteriaGammaproteobacteriaEnterobacteralesEnterobacteriaceaeEscherichia
    Proteomesi
    • UP000000318 Componenti: Chromosome
    • UP000000625 Componenti: Chromosome

    Organism-specific databases

    EcoGeneiEG10542 lon

    Subcellular locationi

    GO - Cellular componenti

    Keywords - Cellular componenti

    Cytoplasm

    Pathology & Biotechi

    Disruption phenotypei

    When both lon and ycgE are disrupted levels of OmpF decrease, leading to lower drug susceptibility, with a greater effect at 26 degrees than at 37 degrees Celsius. The mechanism is not yet understood (PubMed:19721064). Decreased persister cell formation upon antibiotic challenge due probably due to increased levels of MazF toxin (PubMed:24375411). Decreased persister cell formation, further reduced when 10 mRNA toxin interferases are also deleted (PubMed:21788497).3 Publications

    Mutagenesis

    Feature keyPosition(s)DescriptionActionsGraphical viewLength
    Mutagenesisi362K → A: Loss of proteolytic activity and ATP-binding. No increased persister cell formation. 2 Publications1
    Mutagenesisi665H → Y: Loss of proteolytic activity. 1 Publication1
    Mutagenesisi667H → Y: Loss of proteolytic activity. 1 Publication1
    Mutagenesisi676D → N: Loss of proteolytic activity. 1 Publication1
    Mutagenesisi679S → A: Loss of proteolytic activity. No increased persister cell formation. 2 Publications1
    Mutagenesisi743D → N: No effect. 1 Publication1

    PTM / Processingi

    Molecule processing

    Feature keyPosition(s)DescriptionActionsGraphical viewLength
    Initiator methionineiRemovedUniRule annotation1 Publication
    ChainiPRO_00000761332 – 784Lon proteaseAdd BLAST783

    Proteomic databases

    PaxDbiP0A9M0
    PRIDEiP0A9M0

    Expressioni

    Inductioni

    By accumulation of abnormal proteins, such as at high temperatures. Under stress conditions.

    Interactioni

    Subunit structurei

    Homohexamer. Organized in a ring with a central cavity. ATP binding and hydrolysis do not affect the oligomeric state of the enzyme.UniRule annotation1 Publication

    Binary interactionsi

    Protein-protein interaction databases

    BioGridi4260734, 201 interactors
    DIPiDIP-35845N
    IntActiP0A9M0, 72 interactors
    MINTiP0A9M0
    STRINGi316385.ECDH10B_0395

    Structurei

    Secondary structure

    1784
    Legend: HelixTurnBeta strandPDB Structure known for this area
    Show more details

    3D structure databases

    ProteinModelPortaliP0A9M0
    SMRiP0A9M0
    ModBaseiSearch...
    MobiDBiSearch...

    Miscellaneous databases

    EvolutionaryTraceiP0A9M0

    Family & Domainsi

    Domains and Repeats

    Feature keyPosition(s)DescriptionActionsGraphical viewLength
    Domaini11 – 202Lon N-terminalPROSITE-ProRule annotationAdd BLAST192
    Domaini592 – 773Lon proteolyticPROSITE-ProRule annotationAdd BLAST182

    Compositional bias

    Feature keyPosition(s)DescriptionActionsGraphical viewLength
    Compositional biasi211 – 219Arg/Lys-rich (basic)9
    Compositional biasi240 – 252Asp/Glu-rich (acidic)Add BLAST13
    Compositional biasi255 – 270Arg/Lys-rich (basic)Add BLAST16

    Sequence similaritiesi

    Belongs to the peptidase S16 family.UniRule annotation

    Phylogenomic databases

    eggNOGiENOG4105C6P Bacteria
    COG0466 LUCA
    HOGENOMiHOG000261408
    InParanoidiP0A9M0
    KOiK01338
    PhylomeDBiP0A9M0

    Family and domain databases

    Gene3Di3.30.230.10, 1 hit
    HAMAPiMF_01973 lon_bact, 1 hit
    InterProiView protein in InterPro
    IPR003593 AAA+_ATPase
    IPR003959 ATPase_AAA_core
    IPR027543 Lon_bac
    IPR004815 Lon_bac/euk-typ
    IPR008269 Lon_proteolytic
    IPR027065 Lon_Prtase
    IPR003111 Lon_substr-bd
    IPR027417 P-loop_NTPase
    IPR008268 Peptidase_S16_AS
    IPR015947 PUA-like_sf
    IPR020568 Ribosomal_S5_D2-typ_fold
    IPR014721 Ribosomal_S5_D2-typ_fold_subgr
    PANTHERiPTHR10046 PTHR10046, 1 hit
    PfamiView protein in Pfam
    PF00004 AAA, 1 hit
    PF05362 Lon_C, 1 hit
    PF02190 LON_substr_bdg, 1 hit
    PIRSFiPIRSF001174 Lon_proteas, 1 hit
    SMARTiView protein in SMART
    SM00382 AAA, 1 hit
    SM00464 LON, 1 hit
    SUPFAMiSSF52540 SSF52540, 1 hit
    SSF54211 SSF54211, 1 hit
    SSF88697 SSF88697, 1 hit
    TIGRFAMsiTIGR00763 lon, 1 hit
    PROSITEiView protein in PROSITE
    PS51787 LON_N, 1 hit
    PS51786 LON_PROTEOLYTIC, 1 hit
    PS01046 LON_SER, 1 hit

    Sequencei

    Sequence statusi: Complete.

    Sequence processingi: The displayed sequence is further processed into a mature form.

    P0A9M0-1 [UniParc]FASTAAdd to basket
    « Hide
            10         20         30         40         50
    MNPERSERIE IPVLPLRDVV VYPHMVIPLF VGREKSIRCL EAAMDHDKKI
    60 70 80 90 100
    MLVAQKEAST DEPGVNDLFT VGTVASILQM LKLPDGTVKV LVEGLQRARI
    110 120 130 140 150
    SALSDNGEHF SAKAEYLESP TIDEREQEVL VRTAISQFEG YIKLNKKIPP
    160 170 180 190 200
    EVLTSLNSID DPARLADTIA AHMPLKLADK QSVLEMSDVN ERLEYLMAMM
    210 220 230 240 250
    ESEIDLLQVE KRIRNRVKKQ MEKSQREYYL NEQMKAIQKE LGEMDDAPDE
    260 270 280 290 300
    NEALKRKIDA AKMPKEAKEK AEAELQKLKM MSPMSAEATV VRGYIDWMVQ
    310 320 330 340 350
    VPWNARSKVK KDLRQAQEIL DTDHYGLERV KDRILEYLAV QSRVNKIKGP
    360 370 380 390 400
    ILCLVGPPGV GKTSLGQSIA KATGRKYVRM ALGGVRDEAE IRGHRRTYIG
    410 420 430 440 450
    SMPGKLIQKM AKVGVKNPLF LLDEIDKMSS DMRGDPASAL LEVLDPEQNV
    460 470 480 490 500
    AFSDHYLEVD YDLSDVMFVA TSNSMNIPAP LLDRMEVIRL SGYTEDEKLN
    510 520 530 540 550
    IAKRHLLPKQ IERNALKKGE LTVDDSAIIG IIRYYTREAG VRGLEREISK
    560 570 580 590 600
    LCRKAVKQLL LDKSLKHIEI NGDNLHDYLG VQRFDYGRAD NENRVGQVTG
    610 620 630 640 650
    LAWTEVGGDL LTIETACVPG KGKLTYTGSL GEVMQESIQA ALTVVRARAE
    660 670 680 690 700
    KLGINPDFYE KRDIHVHVPE GATPKDGPSA GIAMCTALVS CLTGNPVRAD
    710 720 730 740 750
    VAMTGEITLR GQVLPIGGLK EKLLAAHRGG IKTVLIPFEN KRDLEEIPDN
    760 770 780
    VIADLDIHPV KRIEEVLTLA LQNEPSGMQV VTAK
    Length:784
    Mass (Da):87,438
    Last modified:July 19, 2005 - v1
    Checksum:i4042499C97694EF8
    GO

    Sequence cautioni

    The sequence AAA23537 differs from that shown. Reason: Frameshift at position 16.Curated
    The sequence AAB40195 differs from that shown. Reason: Erroneous initiation. Translation N-terminally shortened.Curated

    Experimental Info

    Feature keyPosition(s)DescriptionActionsGraphical viewLength
    Sequence conflicti264 – 317PKEAK…LRQAQ → RKRQKRKRTGVAEAENDVSD VGRSDRSAWLYRLDGTGAVE CAYEGQKRPASGA in AAA24078 (PubMed:3042779).CuratedAdd BLAST54
    Sequence conflicti273A → R in AAA16837 (PubMed:8226758).Curated1
    Sequence conflicti307S → T in AAA16837 (PubMed:8226758).Curated1
    Sequence conflicti539 – 563AGVRG…LLLDK → RACVVWSVKSPNCVAKRLSS YCSIT in AAA24078 (PubMed:3042779).CuratedAdd BLAST25
    Sequence conflicti772Q → R in AAA16837 (PubMed:8226758).Curated1
    Sequence conflicti779 – 784QVVTAK → HHSLRRRCSTASTYYWAKS in AAA24079 (PubMed:3289547).Curated6

    Sequence databases

    Select the link destinations:
    EMBLi
    GenBanki
    DDBJi
    Links Updated
    L12349 Unassigned DNA Translation: AAC36871.1
    M38347 Genomic DNA Translation: AAA24079.1
    L20572 Unassigned DNA Translation: AAA16837.1
    J03896 Genomic DNA Translation: AAA24078.1
    U82664 Genomic DNA Translation: AAB40195.1 Different initiation.
    U00096 Genomic DNA Translation: AAC73542.1
    AP009048 Genomic DNA Translation: BAE76219.1
    M10153 Genomic DNA Translation: AAA23537.1 Frameshift.
    PIRiA23101
    G64773 SUECLA
    RefSeqiNP_414973.1, NC_000913.3
    WP_001295325.1, NZ_LN832404.1

    Genome annotation databases

    EnsemblBacteriaiAAC73542; AAC73542; b0439
    BAE76219; BAE76219; BAE76219
    GeneIDi945085
    KEGGiecj:JW0429
    eco:b0439
    PATRICifig|1411691.4.peg.1837

    Similar proteinsi

    Cross-referencesi

    Sequence databases

    Select the link destinations:
    EMBLi
    GenBanki
    DDBJi
    Links Updated
    L12349 Unassigned DNA Translation: AAC36871.1
    M38347 Genomic DNA Translation: AAA24079.1
    L20572 Unassigned DNA Translation: AAA16837.1
    J03896 Genomic DNA Translation: AAA24078.1
    U82664 Genomic DNA Translation: AAB40195.1 Different initiation.
    U00096 Genomic DNA Translation: AAC73542.1
    AP009048 Genomic DNA Translation: BAE76219.1
    M10153 Genomic DNA Translation: AAA23537.1 Frameshift.
    PIRiA23101
    G64773 SUECLA
    RefSeqiNP_414973.1, NC_000913.3
    WP_001295325.1, NZ_LN832404.1

    3D structure databases

    Select the link destinations:
    PDBei
    RCSB PDBi
    PDBji
    Links Updated
    PDB entryMethodResolution (Å)ChainPositionsPDBsum
    1QZMX-ray1.90A491-584[»]
    1RR9X-ray2.10A/B/C/D/E/F585-784[»]
    1RREX-ray1.75A/B/C/D/E/F585-784[»]
    2ANEX-ray2.03A/B/C/D/E/F/G/H1-118[»]
    3LJCX-ray2.60A1-245[»]
    ProteinModelPortaliP0A9M0
    SMRiP0A9M0
    ModBaseiSearch...
    MobiDBiSearch...

    Protein-protein interaction databases

    BioGridi4260734, 201 interactors
    DIPiDIP-35845N
    IntActiP0A9M0, 72 interactors
    MINTiP0A9M0
    STRINGi316385.ECDH10B_0395

    Protein family/group databases

    MEROPSiS16.001

    Proteomic databases

    PaxDbiP0A9M0
    PRIDEiP0A9M0

    Protocols and materials databases

    Structural Biology KnowledgebaseSearch...

    Genome annotation databases

    EnsemblBacteriaiAAC73542; AAC73542; b0439
    BAE76219; BAE76219; BAE76219
    GeneIDi945085
    KEGGiecj:JW0429
    eco:b0439
    PATRICifig|1411691.4.peg.1837

    Organism-specific databases

    EchoBASEiEB0537
    EcoGeneiEG10542 lon

    Phylogenomic databases

    eggNOGiENOG4105C6P Bacteria
    COG0466 LUCA
    HOGENOMiHOG000261408
    InParanoidiP0A9M0
    KOiK01338
    PhylomeDBiP0A9M0

    Enzyme and pathway databases

    BioCyciEcoCyc:EG10542-MONOMER
    MetaCyc:EG10542-MONOMER
    BRENDAi3.4.21.53 2026

    Miscellaneous databases

    EvolutionaryTraceiP0A9M0
    PROiPR:P0A9M0

    Family and domain databases

    Gene3Di3.30.230.10, 1 hit
    HAMAPiMF_01973 lon_bact, 1 hit
    InterProiView protein in InterPro
    IPR003593 AAA+_ATPase
    IPR003959 ATPase_AAA_core
    IPR027543 Lon_bac
    IPR004815 Lon_bac/euk-typ
    IPR008269 Lon_proteolytic
    IPR027065 Lon_Prtase
    IPR003111 Lon_substr-bd
    IPR027417 P-loop_NTPase
    IPR008268 Peptidase_S16_AS
    IPR015947 PUA-like_sf
    IPR020568 Ribosomal_S5_D2-typ_fold
    IPR014721 Ribosomal_S5_D2-typ_fold_subgr
    PANTHERiPTHR10046 PTHR10046, 1 hit
    PfamiView protein in Pfam
    PF00004 AAA, 1 hit
    PF05362 Lon_C, 1 hit
    PF02190 LON_substr_bdg, 1 hit
    PIRSFiPIRSF001174 Lon_proteas, 1 hit
    SMARTiView protein in SMART
    SM00382 AAA, 1 hit
    SM00464 LON, 1 hit
    SUPFAMiSSF52540 SSF52540, 1 hit
    SSF54211 SSF54211, 1 hit
    SSF88697 SSF88697, 1 hit
    TIGRFAMsiTIGR00763 lon, 1 hit
    PROSITEiView protein in PROSITE
    PS51787 LON_N, 1 hit
    PS51786 LON_PROTEOLYTIC, 1 hit
    PS01046 LON_SER, 1 hit
    ProtoNetiSearch...

    Entry informationi

    Entry nameiLON_ECOLI
    AccessioniPrimary (citable) accession number: P0A9M0
    Secondary accession number(s): P08177, P78219, Q2MBY7
    Entry historyiIntegrated into UniProtKB/Swiss-Prot: August 1, 1988
    Last sequence update: July 19, 2005
    Last modified: November 7, 2018
    This is version 125 of the entry and version 1 of the sequence. See complete history.
    Entry statusiReviewed (UniProtKB/Swiss-Prot)
    Annotation programProkaryotic Protein Annotation Program

    Miscellaneousi

    Keywords - Technical termi

    3D-structure, Complete proteome, Direct protein sequencing, Reference proteome

    Documents

    1. SIMILARITY comments
      Index of protein domains and families
    2. Peptidase families
      Classification of peptidase families and list of entries
    3. PDB cross-references
      Index of Protein Data Bank (PDB) cross-references
    4. Escherichia coli
      Escherichia coli (strain K12): entries and cross-references to EcoGene
    UniProt is an ELIXIR core data resource
    Main funding by: National Institutes of Health

    We'd like to inform you that we have updated our Privacy Notice to comply with Europe’s new General Data Protection Regulation (GDPR) that applies since 25 May 2018.

    Do not show this banner again