Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
10536972 | Biochimica et Biophysica Acta (BBA) - Proteins and Proteomics | 2010 | 7 Pages |
Abstract
We have studied the structural and enzymatic properties of a diguanylate cyclase from an obligatory anaerobic bacterium Desulfotalea psychrophila, which consists of the N-terminal sensor domain and the C-terminal diguanylate cyclase domain. The sensor domain shows an amino acid sequence homology and spectroscopic properties similar to those of the sensor domains of the globin-coupled sensor proteins containing a protoheme. This heme-containing diguanylate cyclase catalyzes the formation of cyclic di-GMP from GTP only when the heme in the sensor domain binds molecular oxygen. When the heme is in the ferric, deoxy, CO-bound, or NO-bound forms, no enzymatic activity is observed. Resonance Raman spectroscopy reveals that Tyr55 forms a hydrogen bond with the heme-bound O2, but not with CO. Instead, Gln81 interacts with the heme-bound CO. These differences of a hydrogen bonding network will play a crucial role for the selective O2 sensing responsible for the regulation of the enzymatic activity.
Keywords
Related Topics
Physical Sciences and Engineering
Chemistry
Analytical Chemistry
Authors
Hitomi Sawai, Shiro Yoshioka, Takeshi Uchida, Mamoru Hyodo, Yoshihiro Hayakawa, Koichiro Ishimori, Shigetoshi Aono,