3.A.7.9.1
The Icm/Dot or Dot/Icm multicomponent protein secretion system. IcmS and IcmW form a complex that interacts with and may translocate substrate proteins (Ninio et al., 2005; De Buck et al., 2007; Cambronne and Roy, 2007). The crystal structure of the IcmR-IcmQ complex has been solved (Raychaudhury et al., 2009). Legionella pneumophila survives and replicates inside host cells by secreting ~300 effectors through the defective in organelle trafficking (Dot)/intracellular multiplication (Icm) type IVB secretion system (T4BSS). Ghosal et al. 2019, using electron cryotomography mapped the location of the core and accessory components of the Legionella core transmembrane subcomplex, revealing a well-ordered central channel that opens into a large, windowed secretion chamber with an unusual 13-fold symmetry. Immunofluorescence microscopy deciphered an early-stage assembly process that begins with the targeting of Dot/Icm components to the bacterial poles. Polar targeting of this T4BSS is mediated by two Dot/Icm proteins, DotU and IcmF, that are homologues of the T6SS membrane complex components TssL and TssM, suggesting that the Dot/Icm T4BSS is a hybrid system. Thus, the Dot/Icm complex assembles in an 'axial-to-peripheral' pattern (Ghosal et al. 2019).
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| Accession Number: | Q5ZYC1 |
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| Protein Name: | DotG aka IcmE |
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| Length: | 1048 |
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| Molecular Weight: | 107807.00 |
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| Species: | Legionella pneumophila subsp. pneumophila (strain Philadelphia 1 / ATCC 33152 / DSM 7513) [272624] |
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| Number of TMSs: | 2 |
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| Location1 / Topology2 / Orientation3: |
Cell membrane1 / Single-pass membrane protein2 |
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| Substrate |
protein polypeptide chain |
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1: MASKKENLKS LFSNTRTRVI IIFTAALLII AVVIGFFKIR GATTGSIAAA EVSTVPGGIQ
61: SIPGVLDPTA QYAKLQEEQN ITQAQVAEKT GGSAIPTIIR TQALGEGVGV IGSQSGVGFA
121: ALAQEELGGP QRSLWIQELQ DGSCSKSVIT KVVNQGAQLT DLKAACSCVQ LKDSGYGLQE
181: LEQVCECKEL KSAGYNARQL KEAGYSAGRL RNCGFDACEL RNAGFTAQEM KDGGFSDGEL
241: KGAGFSDAEI AKASGLPDGI TADDVRKAGC GAAALAKLRQ AGVSASAIRK ISGCTAEQLK
301: AAGYTAKELK DAGFSAADLR RAGFSAAELK DAGFTARDLL NAGFTPADLA KAGFSDAQIK
361: AAQAELPPGI TPQDVKNAGC DVEALKKERE AGVSAALIRQ YAGCSAQALK AAGFTDADLA
421: NAGFTPAQIS AATPLSDAEI KAAGCDPDKL KKLFSAGVSA KRIKELNGCS AEALKAAGYD
481: AQSLLAAGFT PQELLAAGFT PKQLEDAGLN PVSIIADGRV ADCSVESLKK ARAAGVSALT
541: IKQTLGCSAA ALKAAGYTAK ELKDAGFTAA ELKAAGFSAK ELKDAGFTAK ELRDAGFSAQ
601: ELKDVGFSAK DLKDAGFSAA ELKAAGFTAA QLKAAGFSAK DLKDAGFSAA ELKAAGFSAK
661: ELKDAGFSAS DLKNAGFSAK ELKDAGFSAS DLKSAGFSAS ELKNAGYSAD ELKKAGYTSA
721: ELRNAGFSPQ ESAVAGLQGP DLQQLDSSIT GIPSIPGATP RPTTSDAASS AEQLQAILQK
781: QNEQLAEQKY QQEIQQRTSD MLTAATQLVQ DWKQVETQVY TEGTEETKTS GGESAVPGTG
841: TGTGSNNQPV DQGAVSAQNQ AIIKTGDIMF AVLDTSVNSD EPGPILATIV TGKLKGSKLI
901: GSFNLPSNAD KMVITFNTMS IPGAEKTISI SAYAIDPNTA RTALASRTNH HYLMRYGSLF
961: ASSFLQGFGN AFQSANTTIT IGGTGGGNNI TVANGVGRST LENAVIGLAT VGKAWSQQAQ
1021: QLFNTPTTVE VYSGTGLGIL FTQDVTTI