Limits...
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

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].
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4263535&req=5

biosensors-03-00211-f007: 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].

Mentions: Interestingly, addition of Ec DOS-PAS-A containing the heme Fe(II) complex (Ec DOS-PAS-A-heme Fe(II)) to the full-length enzyme containing a heme Fe(II) complex (Ec DOS-heme Fe(II)) markedly enhanced catalysis (~five-fold), whereas addition of Ec DOS-PAS-A containing the heme Fe(III) complex (Ec DOS-PAS-A-heme Fe(III)) or heme-free (apo) Ec DOS-PAS-A to Ec DOS-heme Fe(II) did not change catalytic activity (Figure 7). In contrast, addition of Ec DOS-PAS-A-heme Fe(II) to an N-terminal PAS-A-truncated Ec DOS deletion mutant did not alter catalytic activity. Thus, the enhanced activity observed upon adding Ec DOS-PAS-A-heme Fe(II) to Ec DOS-heme Fe(II) likely reflects structural changes in the catalytic site resulting from interactions between Ec DOS-PAS-A and the PAS-A domain in the full-length Ec DOS. This protein–protein (PAS-A–PAS-A) interaction was demonstrated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) as well as using a protein microarray system, as shown later. Although the interaction between the isolated PAS sensor domain and the full-length enzyme in this case was artificial, in general, a similar interaction should exist in nature and may be important for as yet unidentified catalytic regulation.


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

Shimizu T - Biosensors (Basel) (2013)

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].
© Copyright Policy - open-access
Related In: Results  -  Collection

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

biosensors-03-00211-f007: 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].
Mentions: Interestingly, addition of Ec DOS-PAS-A containing the heme Fe(II) complex (Ec DOS-PAS-A-heme Fe(II)) to the full-length enzyme containing a heme Fe(II) complex (Ec DOS-heme Fe(II)) markedly enhanced catalysis (~five-fold), whereas addition of Ec DOS-PAS-A containing the heme Fe(III) complex (Ec DOS-PAS-A-heme Fe(III)) or heme-free (apo) Ec DOS-PAS-A to Ec DOS-heme Fe(II) did not change catalytic activity (Figure 7). In contrast, addition of Ec DOS-PAS-A-heme Fe(II) to an N-terminal PAS-A-truncated Ec DOS deletion mutant did not alter catalytic activity. Thus, the enhanced activity observed upon adding Ec DOS-PAS-A-heme Fe(II) to Ec DOS-heme Fe(II) likely reflects structural changes in the catalytic site resulting from interactions between Ec DOS-PAS-A and the PAS-A domain in the full-length Ec DOS. This protein–protein (PAS-A–PAS-A) interaction was demonstrated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) as well as using a protein microarray system, as shown later. Although the interaction between the isolated PAS sensor domain and the full-length enzyme in this case was artificial, in general, a similar interaction should exist in nature and may be important for as yet unidentified catalytic regulation.

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