title: Crystal structure of the response regulator spr1814 from Streptococcus pneumoniae reveals unique interdomain contacts among NarL family proteins.
abstract: Spr1814 belongs to the NarL/FixJ subfamily of signal transduction response regulators (RR), and has been predicted to regulate the neighboring ABC transporter, which translocates antibiotic molecules in Streptococcus pneumoniae. Here, we report the crystal structure of full-length unphosphorylated spr1814 at 1.7Å resolution. The asymmetric unit contains two spr1814 molecules, which display very different conformations. Through comparisons with other RRs structures, we concluded that one molecule adopts a general inactive conformation, whereas the other molecule adopts an intermediate conformation. The superposition of each molecule showed that rotational change of the effector domain occurred in intermediate conformational state, implying that domain rearrangement could occur upon phosphorylation.
authors.affiliation: Division of Biotechnology, College of Life Sciences, Korea University, Seoul 136-713, Republic of Korea.
authors.forename: Ae Kyung
authors.initials: AK
authors.lastname: Park
authors.forename: Jin Ho
authors.initials: JH
authors.lastname: Moon
authors.forename: Jae Soon
authors.initials: JS
authors.lastname: Oh
authors.forename: Ki Seog
authors.initials: KS
authors.lastname: Lee
authors.forename: Young Min
authors.initials: YM
authors.lastname: Chi
mesh_terms: D001426:Bacterial Proteins / Q000737:chemistry* / Q000378:metabolism; D018360:Crystallography, X-Ray; D010766:Phosphorylation; D011487:Protein Conformation; D054730:Protein Interaction Domains and Motifs / Q000502:physiology*; D055503:Protein Multimerization; D017433:Protein Structure, Secondary / Q000502:physiology; D013296:Streptococcus pneumoniae / Q000737:chemistry* / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; C069289:FixJ protein, Bacteria