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Ecto-5'-nucleotidase: Structure function relationships.

Sträter N - Purinergic Signal. (2006)

Bottom Line: The N-terminal domain coordinates two catalytic divalent metal ions, whereas the C-terminal domain provides the substrate specificity pocket for the nucleotides.Thus, the substrate binds at the interface of the two domains.Here, the currently available structural information on ecto-5'-NT is reviewed in relation to the catalytic properties and enzyme function.

View Article: PubMed Central - PubMed

Affiliation: Center for Biotechnology and Biomedicine, University of Leipzig, Deutscher Platz 5, 04103, Leipzig, Germany, strater@bbz.uni-leipzig.de.

ABSTRACT
Ecto-5'-nucleotidase (ecto-5'-NT) is attached via a GPI anchor to the extracellular membrane, where it hydrolyses AMP to adenosine and phosphate. Related 5'-nucleotidases exist in bacteria, where they are exported into the periplasmic space. X-ray structures of the 5'-nucleotidase from E. coli showed that the enzyme consists of two domains. The N-terminal domain coordinates two catalytic divalent metal ions, whereas the C-terminal domain provides the substrate specificity pocket for the nucleotides. Thus, the substrate binds at the interface of the two domains. Here, the currently available structural information on ecto-5'-NT is reviewed in relation to the catalytic properties and enzyme function.

No MeSH data available.


Superposition of the Cα traces of the experimental X-ray structure of E. coli 5′-NT (protein C of PDB ID 1HPU; grey) and the homology model for human 5′-NT. Larger insertions and deletions of the ecto-5′-NT are coloured in magenta and labeled L1 to L7. The closed conformation of E. coli 5′-NT (protein C of PDB ID 1HPU) has been used as template for the homology modelling according to the sequence alignment listed in Fig. 2). The exact loop conformations of longer insertions (L2, L3, L5 and L6) in ecto-5′-NT cannot be modeled with confidence. The experimentally determined disulfide bridges of bovine 5′-NT are shown in yellow and the glycosylated asparagines are shown in red. Depicted in dark blue is the substrate analogue inhibitor α,β-methylene-ADP.
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Fig3: Superposition of the Cα traces of the experimental X-ray structure of E. coli 5′-NT (protein C of PDB ID 1HPU; grey) and the homology model for human 5′-NT. Larger insertions and deletions of the ecto-5′-NT are coloured in magenta and labeled L1 to L7. The closed conformation of E. coli 5′-NT (protein C of PDB ID 1HPU) has been used as template for the homology modelling according to the sequence alignment listed in Fig. 2). The exact loop conformations of longer insertions (L2, L3, L5 and L6) in ecto-5′-NT cannot be modeled with confidence. The experimentally determined disulfide bridges of bovine 5′-NT are shown in yellow and the glycosylated asparagines are shown in red. Depicted in dark blue is the substrate analogue inhibitor α,β-methylene-ADP.

Mentions: A sequence alignment of E. coli 5′-NT and the mammalian ecto-enzymes shows that both domains are conserved and a homology model can be built for ecto-5′-NT (Figs. 2 and 3). The alignment shown in Fig. 2 is manually edited based on an automated sequence alignment and based on information from the generated models in order to fulfill structural constraints such as the possibility to form the known cystine bridges [37] and the necessary insertions and deletions.Fig. 2


Ecto-5'-nucleotidase: Structure function relationships.

Sträter N - Purinergic Signal. (2006)

Superposition of the Cα traces of the experimental X-ray structure of E. coli 5′-NT (protein C of PDB ID 1HPU; grey) and the homology model for human 5′-NT. Larger insertions and deletions of the ecto-5′-NT are coloured in magenta and labeled L1 to L7. The closed conformation of E. coli 5′-NT (protein C of PDB ID 1HPU) has been used as template for the homology modelling according to the sequence alignment listed in Fig. 2). The exact loop conformations of longer insertions (L2, L3, L5 and L6) in ecto-5′-NT cannot be modeled with confidence. The experimentally determined disulfide bridges of bovine 5′-NT are shown in yellow and the glycosylated asparagines are shown in red. Depicted in dark blue is the substrate analogue inhibitor α,β-methylene-ADP.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2254484&req=5

Fig3: Superposition of the Cα traces of the experimental X-ray structure of E. coli 5′-NT (protein C of PDB ID 1HPU; grey) and the homology model for human 5′-NT. Larger insertions and deletions of the ecto-5′-NT are coloured in magenta and labeled L1 to L7. The closed conformation of E. coli 5′-NT (protein C of PDB ID 1HPU) has been used as template for the homology modelling according to the sequence alignment listed in Fig. 2). The exact loop conformations of longer insertions (L2, L3, L5 and L6) in ecto-5′-NT cannot be modeled with confidence. The experimentally determined disulfide bridges of bovine 5′-NT are shown in yellow and the glycosylated asparagines are shown in red. Depicted in dark blue is the substrate analogue inhibitor α,β-methylene-ADP.
Mentions: A sequence alignment of E. coli 5′-NT and the mammalian ecto-enzymes shows that both domains are conserved and a homology model can be built for ecto-5′-NT (Figs. 2 and 3). The alignment shown in Fig. 2 is manually edited based on an automated sequence alignment and based on information from the generated models in order to fulfill structural constraints such as the possibility to form the known cystine bridges [37] and the necessary insertions and deletions.Fig. 2

Bottom Line: The N-terminal domain coordinates two catalytic divalent metal ions, whereas the C-terminal domain provides the substrate specificity pocket for the nucleotides.Thus, the substrate binds at the interface of the two domains.Here, the currently available structural information on ecto-5'-NT is reviewed in relation to the catalytic properties and enzyme function.

View Article: PubMed Central - PubMed

Affiliation: Center for Biotechnology and Biomedicine, University of Leipzig, Deutscher Platz 5, 04103, Leipzig, Germany, strater@bbz.uni-leipzig.de.

ABSTRACT
Ecto-5'-nucleotidase (ecto-5'-NT) is attached via a GPI anchor to the extracellular membrane, where it hydrolyses AMP to adenosine and phosphate. Related 5'-nucleotidases exist in bacteria, where they are exported into the periplasmic space. X-ray structures of the 5'-nucleotidase from E. coli showed that the enzyme consists of two domains. The N-terminal domain coordinates two catalytic divalent metal ions, whereas the C-terminal domain provides the substrate specificity pocket for the nucleotides. Thus, the substrate binds at the interface of the two domains. Here, the currently available structural information on ecto-5'-NT is reviewed in relation to the catalytic properties and enzyme function.

No MeSH data available.