3QH6

1.8A resolution structure of CT296 from Chlamydia trachomatis

Summary for 3QH6

• Entry DOI: 10.2210/pdb3qh6/pdb
• Related: 3QH7
• Descriptor: CT296, TETRAETHYLENE GLYCOL (3 entities in total)
• Functional Keywords: ct296, iron, modeling, chlamydia, unknown function
• Biological source: Chlamydia trachomatis
• Total number of polymer chains: 1
• Total formula weight: 18346.14

Authors

Kemege, K.,Hickey, J.,Lovell, S.,Battaile, K.P.,Zhang, Y.,Hefty, P.S. (deposition date: 2011-01-25, release date: 2011-10-05, Last modification date: 2024-02-21)

Primary citation

Kemege, K.E.,Hickey, J.M.,Lovell, S.,Battaile, K.P.,Zhang, Y.,Hefty, P.S.
Ab initio structural modeling of and experimental validation for Chlamydia trachomatis protein CT296 reveal structural similarity to Fe(II) 2-oxoglutarate-dependent enzymes.
J.Bacteriol., 193:6517-6528, 2011

PubMed Abstract: Chlamydia trachomatis is a medically important pathogen that encodes a relatively high percentage of proteins with unknown function. The three-dimensional structure of a protein can be very informative regarding the protein's functional characteristics; however, determining protein structures experimentally can be very challenging. Computational methods that model protein structures with sufficient accuracy to facilitate functional studies have had notable successes. To evaluate the accuracy and potential impact of computational protein structure modeling of hypothetical proteins encoded by Chlamydia, a successful computational method termed I-TASSER was utilized to model the three-dimensional structure of a hypothetical protein encoded by open reading frame (ORF) CT296. CT296 has been reported to exhibit functional properties of a divalent cation transcription repressor (DcrA), with similarity to the Escherichia coli iron-responsive transcriptional repressor, Fur. Unexpectedly, the I-TASSER model of CT296 exhibited no structural similarity to any DNA-interacting proteins or motifs. To validate the I-TASSER-generated model, the structure of CT296 was solved experimentally using X-ray crystallography. Impressively, the ab initio I-TASSER-generated model closely matched (2.72-Å C(α) root mean square deviation [RMSD]) the high-resolution (1.8-Å) crystal structure of CT296. Modeled and experimentally determined structures of CT296 share structural characteristics of non-heme Fe(II) 2-oxoglutarate-dependent enzymes, although key enzymatic residues are not conserved, suggesting a unique biochemical process is likely associated with CT296 function. Additionally, functional analyses did not support prior reports that CT296 has properties shared with divalent cation repressors such as Fur.

PubMed: 21965559
DOI: 10.1128/JB.05488-11

Experimental method

X-RAY DIFFRACTION (1.8 Å)