1DRM

CRYSTAL STRUCTURE OF THE LIGAND FREE BJFIXL HEME DOMAIN

Replaces:  1BV6

Summary for 1DRM

• Entry DOI: 10.2210/pdb1drm/pdb
• Related: 1BV5 1BV6 1DP6 1DP8 1DP9
• Descriptor: SENSOR PROTEIN FIXL, PROTOPORPHYRIN IX CONTAINING FE (3 entities in total)
• Functional Keywords: fixl, heme domain, pas family, two-component system, histidine kinase, transferase
• Biological source: Bradyrhizobium japonicum
• Total number of polymer chains: 1
• Total formula weight: 15536.34

Authors

Gong, W.,Hao, B.,Mansy, S.S.,Gonzalez, G.,Gilles-Gonzalez, M.A.,Chan, M.K. (deposition date: 2000-01-06, release date: 2000-01-24, Last modification date: 2024-02-07)

Primary citation

Gong, W.,Hao, B.,Mansy, S.S.,Gonzalez, G.,Gilles-Gonzalez, M.A.,Chan, M.K.
Structure of a biological oxygen sensor: a new mechanism for heme-driven signal transduction.
Proc.Natl.Acad.Sci.USA, 95:15177-15182, 1998

PubMed Abstract: The FixL proteins are biological oxygen sensors that restrict the expression of specific genes to hypoxic conditions. FixL's oxygen-detecting domain is a heme binding region that controls the activity of an attached histidine kinase. The FixL switch is regulated by binding of oxygen and other strong-field ligands. In the absence of bound ligand, the heme domain permits kinase activity. In the presence of bound ligand, this domain turns off kinase activity. Comparison of the structures of two forms of the Bradyrhizobium japonicum FixL heme domain, one in the "on" state without bound ligand and one in the "off" state with bound cyanide, reveals a mechanism of regulation by a heme that is distinct from the classical hemoglobin models. The close structural resemblance of the FixL heme domain to the photoactive yellow protein confirms the existence of a PAS structural motif but reveals the presence of an alternative regulatory gateway.

PubMed: 9860942
DOI: 10.1073/pnas.95.26.15177

Experimental method

X-RAY DIFFRACTION (2.4 Å)