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The Heme-Based Oxygen-Sensor Phosphodiesterase Ec DOS (DosP): Structure-Function Relationships.

Shimizu T - Biosensors (Basel) (2013)

Bottom Line: Notably, its activity is markedly enhanced by O2 binding to the heme Fe(II) complex in the PAS sensor domain.X-ray crystal structures and spectroscopic and catalytic characterization of the wild-type and mutant proteins have provided important structural and functional clues to understanding the molecular mechanism of intramolecular catalytic regulation by O2 binding.This review summarizes the intriguing findings that have obtained for Ec DOS.

View Article: PubMed Central - PubMed

Affiliation: Department of Cell Biology, Shantou University Medical College, Shantou 515041, China. shimizu@tagen.tohoku.ac.jp.

ABSTRACT
Escherichia coli Direct Oxygen Sensor (Ec DOS, also known as Ec DosP) is a heme-based O2-sensing phosphodiesterase from Escherichia coli that catalyzes the conversion of cyclic-di-GMP to linear di-GMP. Cyclic-di-GMP is an important second messenger in bacteria, highlighting the importance of understanding structure-function relationships of Ec DOS. Ec DOS is composed of an N-terminal heme-bound O2-sensing PAS domain and a C-terminal phosphodiesterase catalytic domain. Notably, its activity is markedly enhanced by O2 binding to the heme Fe(II) complex in the PAS sensor domain. X-ray crystal structures and spectroscopic and catalytic characterization of the wild-type and mutant proteins have provided important structural and functional clues to understanding the molecular mechanism of intramolecular catalytic regulation by O2 binding. This review summarizes the intriguing findings that have obtained for Ec DOS.

No MeSH data available.


Related in: MedlinePlus

The protein microarray demonstrated that the catalytic activity of Ec DOS is closely associated with its protein–protein interactions [30,31]. Full-length (His)6-tagged Ec DOS was immobilized on a solid surface via an anti-(His)6 monoclonal antibody (mAb). This protein microassay showed that Ec DOS-PAS-A-heme Fe(II) interacted with full-length Ec DOS, whereas Ec DOS-PAS-A-heme Fe(III) or heme-free Ec DOS-PAS-A did not interact with the enzyme. Addition of c-AMP increased the interaction between labeled Ec DOS-PAS-A and full-length Ec DOS, whereas addition of inhibitors decreased this interaction. These findings correspond closely with the catalytic regulation of full-length Ec DOS by Ec DOS-PAS-A (Figure 7) [21]. Adapted from [31].
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biosensors-03-00211-f010: The protein microarray demonstrated that the catalytic activity of Ec DOS is closely associated with its protein–protein interactions [30,31]. Full-length (His)6-tagged Ec DOS was immobilized on a solid surface via an anti-(His)6 monoclonal antibody (mAb). This protein microassay showed that Ec DOS-PAS-A-heme Fe(II) interacted with full-length Ec DOS, whereas Ec DOS-PAS-A-heme Fe(III) or heme-free Ec DOS-PAS-A did not interact with the enzyme. Addition of c-AMP increased the interaction between labeled Ec DOS-PAS-A and full-length Ec DOS, whereas addition of inhibitors decreased this interaction. These findings correspond closely with the catalytic regulation of full-length Ec DOS by Ec DOS-PAS-A (Figure 7) [21]. Adapted from [31].

Mentions: Addition of Ec DOS-PAS-A-heme Fe(II) to full-length Ec DOS-heme Fe(II) enhanced catalytic activity toward c-AMP by five-fold [21]. This catalytic enhancement was not observed upon adding Ec DOS-PAS-A-heme Fe(III) or heme-free (apo) Ec DOS-PAS-A to full-length Ec DOS-heme Fe(II). Furthermore, addition of Ec DOS-PAS-A-heme Fe(II) to PAS-A-truncated Ec DOS did not enhance catalytic activity. Therefore, the enhancement of catalytic activity is likely caused by protein–protein (PAS-A–PAS-A) interaction, as demonstrated by the novel protein microarray [30,31] (see Figure 10). Adapted from [21].


The Heme-Based Oxygen-Sensor Phosphodiesterase Ec DOS (DosP): Structure-Function Relationships.

Shimizu T - Biosensors (Basel) (2013)

The protein microarray demonstrated that the catalytic activity of Ec DOS is closely associated with its protein–protein interactions [30,31]. Full-length (His)6-tagged Ec DOS was immobilized on a solid surface via an anti-(His)6 monoclonal antibody (mAb). This protein microassay showed that Ec DOS-PAS-A-heme Fe(II) interacted with full-length Ec DOS, whereas Ec DOS-PAS-A-heme Fe(III) or heme-free Ec DOS-PAS-A did not interact with the enzyme. Addition of c-AMP increased the interaction between labeled Ec DOS-PAS-A and full-length Ec DOS, whereas addition of inhibitors decreased this interaction. These findings correspond closely with the catalytic regulation of full-length Ec DOS by Ec DOS-PAS-A (Figure 7) [21]. Adapted from [31].
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4263535&req=5

biosensors-03-00211-f010: The protein microarray demonstrated that the catalytic activity of Ec DOS is closely associated with its protein–protein interactions [30,31]. Full-length (His)6-tagged Ec DOS was immobilized on a solid surface via an anti-(His)6 monoclonal antibody (mAb). This protein microassay showed that Ec DOS-PAS-A-heme Fe(II) interacted with full-length Ec DOS, whereas Ec DOS-PAS-A-heme Fe(III) or heme-free Ec DOS-PAS-A did not interact with the enzyme. Addition of c-AMP increased the interaction between labeled Ec DOS-PAS-A and full-length Ec DOS, whereas addition of inhibitors decreased this interaction. These findings correspond closely with the catalytic regulation of full-length Ec DOS by Ec DOS-PAS-A (Figure 7) [21]. Adapted from [31].
Mentions: Addition of Ec DOS-PAS-A-heme Fe(II) to full-length Ec DOS-heme Fe(II) enhanced catalytic activity toward c-AMP by five-fold [21]. This catalytic enhancement was not observed upon adding Ec DOS-PAS-A-heme Fe(III) or heme-free (apo) Ec DOS-PAS-A to full-length Ec DOS-heme Fe(II). Furthermore, addition of Ec DOS-PAS-A-heme Fe(II) to PAS-A-truncated Ec DOS did not enhance catalytic activity. Therefore, the enhancement of catalytic activity is likely caused by protein–protein (PAS-A–PAS-A) interaction, as demonstrated by the novel protein microarray [30,31] (see Figure 10). Adapted from [21].

Bottom Line: Notably, its activity is markedly enhanced by O2 binding to the heme Fe(II) complex in the PAS sensor domain.X-ray crystal structures and spectroscopic and catalytic characterization of the wild-type and mutant proteins have provided important structural and functional clues to understanding the molecular mechanism of intramolecular catalytic regulation by O2 binding.This review summarizes the intriguing findings that have obtained for Ec DOS.

View Article: PubMed Central - PubMed

Affiliation: Department of Cell Biology, Shantou University Medical College, Shantou 515041, China. shimizu@tagen.tohoku.ac.jp.

ABSTRACT
Escherichia coli Direct Oxygen Sensor (Ec DOS, also known as Ec DosP) is a heme-based O2-sensing phosphodiesterase from Escherichia coli that catalyzes the conversion of cyclic-di-GMP to linear di-GMP. Cyclic-di-GMP is an important second messenger in bacteria, highlighting the importance of understanding structure-function relationships of Ec DOS. Ec DOS is composed of an N-terminal heme-bound O2-sensing PAS domain and a C-terminal phosphodiesterase catalytic domain. Notably, its activity is markedly enhanced by O2 binding to the heme Fe(II) complex in the PAS sensor domain. X-ray crystal structures and spectroscopic and catalytic characterization of the wild-type and mutant proteins have provided important structural and functional clues to understanding the molecular mechanism of intramolecular catalytic regulation by O2 binding. This review summarizes the intriguing findings that have obtained for Ec DOS.

No MeSH data available.


Related in: MedlinePlus