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| Operon |  |
|---|---|
| Name: | flhDC |
| This page displays every known transcription unit of this operon and their known regulation. | |
| Name: | flhDC |
| Synonym(s): | OP00183 |
| Gene(s): | flhC, flhD Genome Browser M3D Gene expression COLOMBOS |
| Note(s): | The transcription of the flhDC operon is repressed in acidic phospholipid-deficient cells, but the gadW, metE, and yeaB genes in multicopy suppress this repression through the reduction of overexpression of RpoS caused by the same mutation in the gene producing acidic phospholipid |CITS:[20185506]|. The mechanism for this is not known. Under motility-inducing environmental growth conditions, a motile element (IS5) is inserted into the upstream region of the flhDC operon. This event appears to enhance the expression of the operon, because motility and biofilm formation are increased |CITS:[ 21390082]||CITS: [28100305]|. IS5 insertion disrupts the H-NS binding site, thus preventing transcriptional repression of the operon |CITS:[ 21390082]|. Three novel cis-acting IS elements upstream of flhDC (IS5, located at -166 and -315, IS1, inserted at -303, and a trans-acting missense mutation in lrhA) were found that enhanced motility by relieving transcriptional repression of flhDC |CITS:[23456724]|. Both effects act in parallel, suggesting their apparently independent regulation of flagellar expression |CITS:[23456724]|. Several insertion sequence (IS) elements upstream of the promoter for flhDC stimulate motility independently of orientation and have a long-range effect |CITS:[ 26170415] |. fllhDC expression is enhanced by AtoSC in the presence of acetoacetate |CITS: [22083893]|. Under NlpE outer membrane lipoprotein overexpression, the transcription of the flhC gene is decreased |CITS:[ 23564175]|. Based on mutations analysis, it was shown that OmpR and RcsB abolish temporal and spatial changes in expression of flhDC |CITS:[23914787]|. Single nucleotide changes in the -10 element and the spacer of the flhDC promoter, and also in the cAMP-CRP-binding region, increase motility |CITS:[ 26170415]|. Several mutations in the flhDC promoter allow motility in H-NS mutant strains |CITS:[ 26170415]|. YjjQ represses transcription of the flhDC operon independently from the previously characterized RcsA-RcsB repressor, even though the two DNA-binding motifs contain overlapping sequences |CITS:[26078445]|. flhDC requires a specific transcription rate to maintain optimal flagellum numbers |CITS:[30420601]|. The impact of a two-component signal transduction system (2CSTS) was reviewed with regard to EnvZ/OmpT, RscCDB, CheAYB, and QueCB. Studies of the effects of changes in signaling on the expression of motility and biofilm genes revealed the involvement of the flhDC operon in the induction of changes in motility in the early phases of biofilm development and the swim-or-stick switch that allows bacteria to transit from reversible to irreversible attachment |CITS: [28533218]|. Orthologous flhDC from E. coli can functionally complement flhDC in S. Enterica, and flhCEC is not functionally identical to flhCST |CITS:[30420601]|. The phenotypic differences between species arise from adaptations during evolution to expand or modify cellular function with respect to movement within specific environmental niches |CITS:[30420601]|. |
| Evidence: | [LTED] Length of transcript experimentally determined |
| Reference(s): |
[1] Bertin P., et al., 1994 [2] Lehti TA., et al., 2012 [3] Shin S., et al., 1995 |
| Promoter | |
| Name: | flhDp |
| +1: | 1978395 |
| Sigma Factor: | Sigma70 Sigmulon |
| Distance from start of the gene: | 198 |
| Sequence: |
tattgaaaatcgcagcccccctccgttgtatgtgcgtgtagtgacgagtacagttgcgtcGatttaggaaaaatcttagat -10 -35 +1 |
| Evidence: |
[TIM] ; Method: Primer Extension [TIM] |
| Reference(s): |
[4] Barker CS., et al., 2004 [3] Shin S., et al., 1995 [5] Soutourina O., et al., 1999 [6] Wei BL., et al., 2001 |
| Terminator(s) | |
| Type: | rho-independent |
| Sequence: | ttaacgcgcgATTGGGGCAAAAAAAAGCAGCGGTACGTCGTTACCGCTGCTGGAATGTTGCGCCTcaccgtatca |
| Reference(s): |
[7] Feng CQ., et al., 2018 [8] Lesnik EA., et al., 2001 |
| Type | Transcription factor | Function | Promoter | Binding Sites | Growth Conditions | Evidence (Confirmed, Strong, Weak) | Reference(s) | |||
|---|---|---|---|---|---|---|---|---|---|---|
| LeftPos | RightPos | Central Rel-Pos | Sequence | |||||||
| proximal | CRP-cAMP | activator | flhDp | 1978456 | 1978477 | -71.5 | attgagtgttTTGTGTGATCTGCATCACGCATtattgaaaat | nd | [BPP], [GEA], [HIBSCS] | [5], [10], [11], [12] |
| Type | Transcription factor | Function | Promoter | Binding Sites | Growth Conditions | Evidence (Confirmed, Strong, Weak) | Reference(s) | |||
|---|---|---|---|---|---|---|---|---|---|---|
| LeftPos | RightPos | Central Rel-Pos | Sequence | |||||||
| proximal | OmpR-P | repressor | flhDp | 1978368 | 1978387 | 18.5 | tcgatttaggAAAAATCTTAGATAAGTGTAaagacccatt | nd | [HIBSCS] | [3] |
| remote | OmpR-P | repressor | flhDp | 1978531 | 1978550 | -145.5 | caaagtcatcGGGCATTATCTGAACATAAAacactatcaa | nd | [HIBSCS] | [3] |
| Note(s): |
1No DNA consensus sequence that is recognized by FliZ has been established. Therefore, for this DNA-binding site we added the complete region, determined by footprinting analysis Pesavento C,2012 to which FliZ binds.1MatA-flhDp regulatory interaction was identified in Escherichia coli strain IHE 3034 Lehti TA,2012 MatA binds with higher affinity to flhDp than flhDp2 Lehti TA,2012 1The binding of the RcsAB heterodimer might sterically prevent the accessibility of the flhDC promoter to the RNA polymerase, or alternatively it might lead to premature transcription termination.7The binding of the RcsAB heterodimer might sterically prevent the accessibility of the flhDC promoter to the RNA polymerase, or alternatively it might lead to premature transcription termination. 8No DNA consensus sequence that is recognized by FliZ has been established. Therefore, for this DNA-binding site we added the complete region, determined by footprinting analysis Pesavento C,2012 to which FliZ binds. 13MatA-flhDp regulatory interaction was identified in Escherichia coli strain IHE 3034 Lehti TA,2012 MatA binds with higher affinity to flhDp than flhDp2 Lehti TA,2012 |
| Name: | flhDC |
| Gene(s): | flhC, flhD Genome Browser M3D Gene expression COLOMBOS |
| Note(s): | The transcription of the flhDC operon is repressed in acidic phospholipid-deficient cells, but the gadW, metE, and yeaB genes in multicopy suppress this repression through the reduction of overexpression of RpoS caused by the same mutation in the gene producing acidic phospholipid |CITS:[20185506]|. The mechanism for this is not known. Under motility-inducing environmental growth conditions, a motile element (IS5) is inserted into the upstream region of the flhDC operon. This event appears to enhance the expression of the operon, because motility and biofilm formation are increased |CITS:[ 21390082]|. IS5 insertion disrupts the H-NS binding site, thus preventing transcriptional repression of the operon |CITS:[ 21390082]| |
| Reference(s): |
[1] Bertin P., et al., 1994 [3] Shin S., et al., 1995 |
| Promoter | |
| Name: | flhDp2 |
| +1: | 1978577 |
| Sigma Factor: | Sigma54 Sigmulon |
| Distance from start of the gene: | 380 |
| Sequence: |
aacctgaatctgaggcagcacctggcacggctgggacggaagtcgctgtcgttctcaaaaTcggtggagctgcatgacaaa -12 -24 +1 |
| Note(s): | This promoter was identified by microarray assays with a mutant σ54 strain and a σ54-overexpressing strain, and by σ54-related promoter element identification Zhao K,2010 We assigned a putative transcription start site to this promoter based on the observation that the majority of the σ54-dependent promoters, whose transcription start sites were determined experimentally, present a distance of 11 nucleotides between the transcription start site and the -12 box Barrios H,1999. |
| Evidence: |
[HIPP] [IEP] |
| Reference(s): | [21] Zhao K., et al., 2010 |
| Terminator(s) | |
| Type: | rho-independent |
| Sequence: | ttaacgcgcgATTGGGGCAAAAAAAAGCAGCGGTACGTCGTTACCGCTGCTGGAATGTTGCGCCTcaccgtatca |
| Reference(s): |
[7] Feng CQ., et al., 2018 [8] Lesnik EA., et al., 2001 |
| Note(s): |
1MatA-flhDp2 regulatory interaction was identified in Escherichia coli strain IHE 3034 Lehti TA,2012 MatA binds with higher affinity to flhDp than flhDp2 Lehti TA,20121MatA-flhDp2 regulatory interaction was identified in Escherichia coli strain IHE 3034 Lehti TA,2012 MatA binds with higher affinity to flhDp than flhDp2 Lehti TA,2012 |
| RNA cis-regulatory element | |
|---|
| Regulation, transcriptional elongation | |
| Attenuator type: | Translational |
| Strand: | reverse |
| Evidence: | [ICA] Inferred by computational analysis |
| Reference(s): | [22] null null |
| Structure type | Energy | LeftPos | RightPos | Sequence (RNA-strand) | |
|---|---|---|---|---|---|
| terminator | -8.4 | 1978230 | 1978246 | acatcacgggGTGCGGTGAAACCGCAtaaaaataaa |
| Notes: "The provided "Sequence" is that of the RNA strand, i.e. U's are shown instead of T's and regulators on the reverse strand will appear as the reverse complement of the sequence delimited by LeftPos-RigtPos" |
| Reference(s) |
|
|---|---|
[TIM] Transcription initiation mapping