3bsqA Discussion: Difference between revisions

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'''Multiple sequence alighment''' (MSA) revealed some conserved residues throughput the whole sulfatase family. Previous experiemnts on catalytic activity of sulfatases describe a set of residues which are essential for the function of sulfatases. A histidine residue (H)  and two or more '''''sequential''''' arganine residues (R) are known to be essential, and also characteristic of the N-terminal active site of sulfatases. Our MSA resultaed a number of residues conserves in the N-terminus, along with a H and one R residue. When these conserved residues were marked in the three dimenetional view of ASK in '''PyMol''', they all seemed clustered within a certain region of the molecule. This region is found in the core of the molecule, directly inside a pocket-like surface feature. This region is assumed to be the 'possible active site' of the protein.
'''Multiple sequence alighment''' (MSA) revealed some conserved residues throughput the whole sulfatase family. Previous experiemnts on catalytic activity of sulfatases describe a set of residues which are essential for the function of sulfatases. A histidine residue (H)  and two or more '''''sequential''''' arganine residues (R) are known to be essential, and also characteristic of the N-terminal active site of sulfatases. Our MSA resultaed a number of residues conserves in the N-terminus, along with a H and one R residue. When these conserved residues were marked in the three dimenetional view of ASK in '''PyMol''', they all seemed clustered within a certain region of the molecule. This region is found in the core of the molecule, directly inside a pocket-like surface feature. This region is assumed to be the 'possible active site' of the protein.


Previous investigation has revealed that arylsulfatases D,E,F,G,H,J snd K are localysed in ER and golgi compartments of the cell ([[http://www.ncbi.nlm.nih.gov/pubmed/17558559?ordinalpos=2&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVDocSum]] Ghosh, D., 2007). Human Steroid sulfatase (STS) which has similar sequence fratures to ASK is also localysed in ER.  However STS is a membrane bound protein which consists of a globular domain bearing the catalytic site and a transmembrane domain made up of two antiparallel hydrophobic alpha helices (Ghosh, D., 2007).  Structural features of ASK do not show an transmembrane domain, therfore it has to be a metrix soluble enzyme.  
Previous investigation has revealed that arylsulfatases D,E,F,G,H,J snd K are localysed in ER and golgi compartments of the cell ([[http://www.ncbi.nlm.nih.gov/pubmed/17558559?ordinalpos=2&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVDocSum]] Ghosh, D., 2007). Human Steroid sulfatase (STS) which has similar sequence fratures to ASK is also localysed in ER.  However STS is a membrane bound protein which consists of a globular domain bearing the catalytic site and a transmembrane domain made up of two antiparallel hydrophobic alpha helices (Ghosh, D., 2007).  Structural features of ASK do not show an transmembrane domain, therfore it has to be a metrix soluble enzyme.
 
Studies on the catalytic site of sulfatases, especially in the studies with STS, ASA and ASB, it is observed that catalytic site is compsoed with a set of very highly conserved residues; which include Asp, Cys, Arg, Lys and His. the site is also observed deep insind the molecule connected by a hydrophobic substrate entry path.  


Results of structural comparisons and protein-protein interactions resulted several other proteins, which were used for a second multiple sequence alighment. This alighment also showed a certain degree of conservation of previously described conserved residues.
Results of structural comparisons and protein-protein interactions resulted several other proteins, which were used for a second multiple sequence alighment. This alighment also showed a certain degree of conservation of previously described conserved residues.

Revision as of 10:03, 2 June 2008

Multiple sequence alighment (MSA) revealed some conserved residues throughput the whole sulfatase family. Previous experiemnts on catalytic activity of sulfatases describe a set of residues which are essential for the function of sulfatases. A histidine residue (H) and two or more sequential arganine residues (R) are known to be essential, and also characteristic of the N-terminal active site of sulfatases. Our MSA resultaed a number of residues conserves in the N-terminus, along with a H and one R residue. When these conserved residues were marked in the three dimenetional view of ASK in PyMol, they all seemed clustered within a certain region of the molecule. This region is found in the core of the molecule, directly inside a pocket-like surface feature. This region is assumed to be the 'possible active site' of the protein.

Previous investigation has revealed that arylsulfatases D,E,F,G,H,J snd K are localysed in ER and golgi compartments of the cell ([[1]] Ghosh, D., 2007). Human Steroid sulfatase (STS) which has similar sequence fratures to ASK is also localysed in ER. However STS is a membrane bound protein which consists of a globular domain bearing the catalytic site and a transmembrane domain made up of two antiparallel hydrophobic alpha helices (Ghosh, D., 2007). Structural features of ASK do not show an transmembrane domain, therfore it has to be a metrix soluble enzyme.

Studies on the catalytic site of sulfatases, especially in the studies with STS, ASA and ASB, it is observed that catalytic site is compsoed with a set of very highly conserved residues; which include Asp, Cys, Arg, Lys and His. the site is also observed deep insind the molecule connected by a hydrophobic substrate entry path.

Results of structural comparisons and protein-protein interactions resulted several other proteins, which were used for a second multiple sequence alighment. This alighment also showed a certain degree of conservation of previously described conserved residues.