title: Structural and functional characterizations of SsgB, a conserved activator of developmental cell division in morphologically complex actinomycetes.
abstract: SsgA-like proteins (SALPs) are a family of homologous cell division-related proteins that occur exclusively in morphologically complex actinomycetes. We show that SsgB, a subfamily of SALPs, is the archetypal SALP that is functionally conserved in all sporulating actinomycetes. Sporulation-specific cell division of Streptomyces coelicolor ssgB mutants is restored by introduction of distant ssgB orthologues from other actinomycetes. Interestingly, the number of septa (and spores) of the complemented null mutants is dictated by the specific ssgB orthologue that is expressed. The crystal structure of the SsgB from Thermobifida fusca was determined at 2.6 A resolution and represents the first structure for this family. The structure revealed similarities to a class of eukaryotic "whirly" single-stranded DNA/RNA-binding proteins. However, the electro-negative surface of the SALPs suggests that neither SsgB nor any of the other SALPs are likely to interact with nucleotide substrates. Instead, we show that a conserved hydrophobic surface is likely to be important for SALP function and suggest that proteins are the likely binding partners.
authors: Joint Center for Structural Genomics, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA.
authors: Qingping
authors: Q
authors: Xu
authors: Bjørn A
authors: BA
authors: Traag
authors: Joost
authors: J
authors: Willemse
authors: Daniel
authors: D
authors: McMullan
authors: Mitchell D
authors: MD
authors: Miller
authors: Marc-André
authors: MA
authors: Elsliger
authors: Polat
authors: P
authors: Abdubek
authors: Tamara
authors: T
authors: Astakhova
authors: Herbert L
authors: HL
authors: Axelrod
authors: Constantina
authors: C
authors: Bakolitsa
authors: Dennis
authors: D
authors: Carlton
authors: Connie
authors: C
authors: Chen
authors: Hsiu-Ju
authors: HJ
authors: Chiu
authors: Maksymilian
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authors: Chruszcz
authors: Thomas
authors: T
authors: Clayton
authors: Debanu
authors: D
authors: Das
authors: Marc C
authors: MC
authors: Deller
authors: Lian
authors: L
authors: Duan
authors: Kyle
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authors: Ellrott
authors: Dustin
authors: D
authors: Ernst
authors: Carol L
authors: CL
authors: Farr
authors: Julie
authors: J
authors: Feuerhelm
authors: Joanna C
authors: JC
authors: Grant
authors: Anna
authors: A
authors: Grzechnik
authors: Slawomir K
authors: SK
authors: Grzechnik
authors: Gye Won
authors: GW
authors: Han
authors: Lukasz
authors: L
authors: Jaroszewski
authors: Kevin K
authors: KK
authors: Jin
authors: Heath E
authors: HE
authors: Klock
authors: Mark W
authors: MW
authors: Knuth
authors: Piotr
authors: P
authors: Kozbial
authors: S Sri
authors: SS
authors: Krishna
authors: Abhinav
authors: A
authors: Kumar
authors: David
authors: D
authors: Marciano
authors: Wladek
authors: W
authors: Minor
authors: A Mieke
authors: AM
authors: Mommaas
authors: Andrew T
authors: AT
authors: Morse
authors: Edward
authors: E
authors: Nigoghossian
authors: Amanda
authors: A
authors: Nopakun
authors: Linda
authors: L
authors: Okach
authors: Silvya
authors: S
authors: Oommachen
authors: Jessica
authors: J
authors: Paulsen
authors: Christina
authors: C
authors: Puckett
authors: Ron
authors: R
authors: Reyes
authors: Christopher L
authors: CL
authors: Rife
authors: Natasha
authors: N
authors: Sefcovic
authors: Henry J
authors: HJ
authors: Tien
authors: Christine B
authors: CB
authors: Trame
authors: Henry
authors: H
authors: van den Bedem
authors: Shuren
authors: S
authors: Wang
authors: Dana
authors: D
authors: Weekes
authors: Keith O
authors: KO
authors: Hodgson
authors: John
authors: J
authors: Wooley
authors: Ashley M
authors: AM
authors: Deacon
authors: Adam
authors: A
authors: Godzik
authors: Scott A
authors: SA
authors: Lesley
authors: Ian A
authors: IA
authors: Wilson
authors: Gilles P
authors: GP
authors: van Wezel
mesh_terms: D039903:Actinobacteria / Q000378:metabolism*; D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry* / Q000502:physiology*; D001665:Binding Sites; D002455:Cell Division; D020285:Cryoelectron Microscopy; D018360:Crystallography, X-Ray / Q000379:methods; D004926:Escherichia coli / Q000378:metabolism; D005816:Genetic Complementation Test; D008856:Microscopy, Fluorescence / Q000379:methods; D008858:Microscopy, Phase-Contrast / Q000379:methods; D008969:Molecular Sequence Data; D009154:Mutation; D017386:Sequence Homology, Amino Acid; D013171:Spores, Bacterial
chemical_list: D001426:Bacterial Proteins; C462919:ssgB protein, Streptomyces coelicolor