5XAZ

Crystal structure of full length native tylp, a tetr regulator from streptomyces fradiae

Summary for 5XAZ

• Entry DOI: 10.2210/pdb5xaz/pdb
• Related: 5XAY
• Descriptor: Gamma-butyrolactone receptor protein (2 entities in total)
• Functional Keywords: tetr family, transcription regulator, antibiotic regulation, hth dna binding domain, dna binding protein
• Biological source: Streptomyces fradiae
• Total number of polymer chains: 8
• Total formula weight: 200125.22

Authors

Ray, S.,Panjikar, S.,Anand, R. (deposition date: 2017-03-15, release date: 2017-08-02, Last modification date: 2024-03-27)

Primary citation

Ray, S.,Maitra, A.,Biswas, A.,Panjikar, S.,Mondal, J.,Anand, R.
Functional insights into the mode of DNA and ligand binding of the TetR family regulator TylP from Streptomyces fradiae
J. Biol. Chem., 292:15301-15311, 2017

PubMed Abstract: Tetracycline repressors (TetRs) modulate multidrug efflux pathways in several pathogenic bacteria. In , they additionally regulate secondary metabolic pathways like antibiotic production. For instance, in the antibiotic producer a layered network of TetRs regulates the levels of the commercially important antibiotic tylosin, with TylP occupying the top of this cascading network. TetRs exist in two functional states, the DNA-bound and the ligand-bound form, which are allosterically regulated. Here, to develop deeper insights into the factors that govern allostery, the crystal structure of TylP was solved to a resolution of 2.3 Å. The structure revealed that TylP possesses several unique features; notably, it harbors a unique C-terminal helix-loop extension that spans the entire length of the structure. This anchor connects the DNA-binding domain (DBD) with the ligand-binding domain (LBD) via a mix of positively charged and hydrogen-bonding interactions. Supporting EMSA studies with a series of ΔC truncated versions show that a systematic deletion of this region results in complete loss of DNA binding. The structure additionally revealed that TylP is markedly different in the orientation of its DBD and LBD architecture and the dimeric geometry from its hypothesized homologue CprB, which is a γ-butyrolactone regulator. Rather, TylP is closer in structural design to macrolide-binding TetRs found in pathogens. Supporting molecular dynamic studies suggested that TylP binds a macrolide intermediate in the tylosin pathway. Collectively, the structure along with corroborating biochemical studies provided insights into the novel mode of regulation of TetRs in antibiotic-producing organisms.

PubMed: 28739805
DOI: 10.1074/jbc.M117.788000

Experimental method

X-RAY DIFFRACTION (2.3 Å)