Protein Family Models

FlgM binds and inhibits the activity of the transcription factor sigma 28. Inhibition of sigma 28 prevents the expression of genes from flagellar transcriptional class 3, which include genes for the filament and chemotaxis. Correctly assembled basal body-hook structures export FlgM, relieving inhibition of sigma 28 and allowing expression of class 3 genes. NMR studies show that free FlgM is mostly unfolded, which may facilitate its export. The C terminal half of FlgM adopts a tertiary structure when it binds to sigma 28. All mutations in FlgM that prevent sigma 28 inhibition affect the C-terminal domain and is the region thought to constitute the binding domain. A minimal binding domain has been identified between Glu 64 and Arg 88 in Salmonella typhimurium (Swiss:P26477). The N-terminal portion remains unstructured and may be necessary for recognition by the export machinery [1]. [1]. 9095196. The C-terminal half of the anti-sigma factor, FlgM, becomes structured when bound to its target, sigma 28. Daughdrill GW, Chadsey MS, Karlinsey JE, Hughes KT, Dahlquist FW;. Nat Struct Biol 1997;4:285-291. [2]. 15068809. Crystal structure of the flagellar sigma/anti-sigma complex sigma(28)/FlgM reveals an intact sigma factor in an inactive conformation. Sorenson MK, Ray SS, Darst SA;. Mol Cell 2004;14:127-138. (from Pfam)

Date:

2024-10-16

flagellar biosynthesis anti-sigma factor FlgM binds and inhibits the activity of the transcription factor sigma 28

Date:

2018-05-01

FlgM interacts with and inhibits the alternative sigma factor sigma(28) FliA [1,2,3]. The C-terminus of FlgM contains the sigma(28)-binding domain [1].

Gene:

flgM

Date:

2021-07-30