Steve Ealick's Research Group
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Steve Ealick's Research Group |
Purine 2'-Deoxyribosyltransferase
PDB files:
1S2L native enzyme
1S2I complex with 6-bromopurine
1S3F complex with SeIno (6-selenoinosine)
1S2D complex with arabinoside: ribosylated intermediate (Araa)
1S2G complex with 2'-deoxyadenosine
Description:
Purine 2'-deoxyribosyltransferase (PTD) is a class I N-deoxyribosyltransferases which is specific for the transfer of deoxyribose between two purines (Pur <--> Pur) with a preference of deoxyinosine (dIno) > deoxyadenosine (dAdo) > deoxyguanosine (dGuo) as the donor substrate. Class II N-deoxyribosyltransferases such as nucleoside trans-deoxyribosylase (NTD) can also catalyze deoxyriboxe transfers between pyrimidines and/or purines. The structure of PTD from Lactobacillus helveticus was solved using NTD (also determined in this laboratory) as a search model.
| The PTD monomer is very similar to the structure of NTD and consists of a central core structure with a five-stranded parallel b-sheets, flanked by four helices. |
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| The active form of PTD is a hexamer that packs as a trimer of dimers. As in NTD, there is one active site per monomer and each catalytic site requires participation from a neighboring subunit. |
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| The active site of PTD shows bound substrate dAdo with key residues and hydrogen bonding patterns. In the paper we also show complexes of other species bound to the active site. |
Click the image to enlarge. |
Reference:
Anand R, Kaminski PA and Ealick SE. Structures of Purine 2'-Deoxyribosyltransferase, Substrate Complexes and the Ribosylated Enzyme Intermediate at 2.0 Å Resolution. Biochemistry 43:2384-2393 (2004).
