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Insights into Biofilm Dispersal Regulation from the Crystal Structure of the PAS-GGDEF-EAL Region of RbdA from Pseudomonas aeruginosa.
Liu, Chong; Liew, Chong Wai; Wong, Yee Hwa; Tan, Siok Thing; Poh, Wee Han; Manimekalai, Malathy S S; Rajan, Sreekanth; Xin, Lingyi; Liang, Zhao-Xun; Grüber, Gerhard; Rice, Scott A; Lescar, Julien.
Afiliação
  • Liu C; School of Biological Sciences, Nanyang Technological University, Singapore, Singapore.
  • Liew CW; Nanyang Institute of Structural Biology, Nanyang Technological University, Singapore, Singapore.
  • Wong YH; School of Biological Sciences, Nanyang Technological University, Singapore, Singapore.
  • Tan ST; Nanyang Institute of Structural Biology, Nanyang Technological University, Singapore, Singapore.
  • Poh WH; School of Biological Sciences, Nanyang Technological University, Singapore, Singapore.
  • Manimekalai MSS; Nanyang Institute of Structural Biology, Nanyang Technological University, Singapore, Singapore.
  • Rajan S; Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore, Singapore.
  • Xin L; Interdisciplinary Graduate School, Nanyang Technological University, Singapore, Singapore.
  • Liang ZX; School of Biological Sciences, Nanyang Technological University, Singapore, Singapore.
  • Grüber G; School of Biological Sciences, Nanyang Technological University, Singapore, Singapore.
  • Rice SA; Nanyang Institute of Structural Biology, Nanyang Technological University, Singapore, Singapore.
  • Lescar J; School of Biological Sciences, Nanyang Technological University, Singapore, Singapore.
J Bacteriol ; 200(3)2018 02 01.
Article em En | MEDLINE | ID: mdl-29109186
ABSTRACT
RbdA is a positive regulator of biofilm dispersal of Pseudomonas aeruginosa Its cytoplasmic region (cRbdA) comprises an N-terminal Per-ARNT-Sim (PAS) domain followed by a diguanylate cyclase (GGDEF) domain and an EAL domain, whose phosphodiesterase activity is allosterically stimulated by GTP binding to the GGDEF domain. We report crystal structures of cRbdA and of two binary complexes one with GTP/Mg2+ bound to the GGDEF active site and one with the EAL domain bound to the c-di-GMP substrate. These structures unveil a 2-fold symmetric dimer stabilized by a closely packed N-terminal PAS domain and a noncanonical EAL dimer. The autoinhibitory switch is formed by an α-helix (S-helix) immediately N-terminal to the GGDEF domain that interacts with the EAL dimerization helix (α6-E) of the other EAL monomer and maintains the protein in a locked conformation. We propose that local conformational changes in cRbdA upon GTP binding lead to a structure with the PAS domain and S-helix shifted away from the GGDEF-EAL domains, as suggested by small-angle X-ray scattering (SAXS) experiments. Domain reorientation should be facilitated by the presence of an α-helical lever (H-helix) that tethers the GGDEF and EAL regions, allowing the EAL domain to rearrange into an active dimeric conformation.IMPORTANCE Biofilm formation by bacterial pathogens increases resistance to antibiotics. RbdA positively regulates biofilm dispersal of Pseudomonas aeruginosa The crystal structures of the cytoplasmic region of the RbdA protein presented here reveal that two evolutionarily conserved helices play an important role in regulating the activity of RbdA, with implications for other GGDEF-EAL dual domains that are abundant in the proteomes of several bacterial pathogens. Thus, this work may assist in the development of small molecules that promote bacterial biofilm dispersal.
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Texto completo: 1 Coleções: 01-internacional Base de dados: MEDLINE Idioma: En Ano de publicação: 2018 Tipo de documento: Article

Texto completo: 1 Coleções: 01-internacional Base de dados: MEDLINE Idioma: En Ano de publicação: 2018 Tipo de documento: Article