User:Ramiro Barrantes/FpgNeiRepair
From Proteopedia
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| <scene name='User:Ramiro_Barrantes/Workbench/Gstfpgneil1covariate/1' target="fpg">E137,R58,G135,L134</scene> | | <scene name='User:Ramiro_Barrantes/Workbench/Gstfpgneil1covariate/1' target="fpg">E137,R58,G135,L134</scene> | ||
| - | | <scene name='User:Ramiro_Barrantes/Workbench/ | + | | <scene name='User:Ramiro_Barrantes/Workbench/Neil1lys60support/1' target="ecoNei">Covariation with Asn172</scene> |
| Y || Y || N || N || Y || Y || Y || Y || Y || N | | Y || Y || N || N || Y || Y || Y || Y || Y || N | ||
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Revision as of 19:12, 21 May 2009
The FpgNei Protein Superfamily
Functional Units
| G. Stereothermophilus Fpg | E. Coli Nei | ||||||||||||
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| Functional Cluster | Variant 1 | Variant 2 | Fpg1 | Fpg2 | Plant | Neil1 | Neil2 | Neil3 | Proteo | Actino1 | Actino2 | MimiVirus |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Support for perfectly conserved Asn168 | Y | Y | N | N | N | N | N | N | N | N | ||
| Stability of catalytic helix | Y | Y | Y | N | N | N | N | N | N | N | ||
| Stability of intercalation loop | Y | Y | Y | N | N | N | N | N | N | Y | ||
| Intercalation loop | Y | Y | Y | N | N | N | N | N | N | Y | ||
| Zinc finger | Y | Y | N | N | Y | Y | Y | Y | Y | N | ||
| Recognition complex | none | Y | N | N | N | N | N | N | N | N | N | |
| Support for Lys60 | Y | Y | N | N | Y | Y | Y | Y | Y | N |
Functional Cluster: Stability of perfectly conserved Asn168
Asn74, along with two other amino acids have an effect in the orientation and kinking of the DNA. In 4 of the 9 clades (Fpg1, Fpg2 and Plants and Fungi) Asn174 is supported by Lys160, which in turn hydrogen bonds with Leu249 and Ser250. In the other clades (Actinobacteria 1 and 2, Proteacteria and all vertebrate sequences), Arg171 that comes from a different helix fulfills the same roles as Lys160. One important difference is that the Zinc Finger is shaped differently in the absence of DNA, and there is a hydrogen bond between one of the beta-sheets and the arginine. One hypothesis is that the arginine or the lysine is necessary to support the Asn174, crucial for orientation of the DNA.
Functional Cluster: Stability of catalytic helix
The triad Leu4, Glu8 and Arg57 interact and provide stability to helixA, which has the catalytic residue Pro2,Glu3 and Glu6. This triad is present in the same four clades as above (Fpg1, Fpg2 and Plants and Fungi). This triad is not present in the remaining clades and it is not clear how the same stability is provided. Leu211 also has a hydrophobic interaction with Leu4.
Functional Cluster: Stability of intercalation loop
Image:IntercalationLoopSupport.jpg
This structure provides stability for the amino acids that insert into the space vacated by the damaged base
Functional Cluster: Stability of key Gly59 and Lys60
Gly59 and Lys60 are important in the activity of MutM. We hypothesize that Glu137 is very important to maintain its stability, this amino acid is compensated by Asn172 in Neil1 </ref>
Functional Cluster: Intercalation Loop
Image:IntercalationLoop.jpg
The residue in positions 77 and 78 suggest a possible intercalation loop
Functional Cluster: Zinc/zincless finger
The Zinc finger serves to support the Arg264 which binds to the phosphate of the damaged base. In Neil1, there is no Zinc but there is an equivalent structure [1]. Both the plants and mimivirus have a zincless finger, although it is not clear if this one is homologousFunctional Cluster: Recognition Complex
This complex is key in recognizing a damaged guanine[2]
Evolution
The FpgNei evolution has not been easy to resolve [3], especially in the deeper branches. Assuming that functional clusters evolve more slowly than individual residues, we can use this as phylogenetic characters to 1) draw the most parsimonious evolution of the superfamily as dictated by these functional clusters 2) examine how these clusters have evolved and how this might have influenced the evolution of FpgNei.
References
- ↑ Doublie S, Bandaru V, Bond JP, Wallace SS. The crystal structure of human endonuclease VIII-like 1 (NEIL1) reveals a zincless finger motif required for glycosylase activity. Proc Natl Acad Sci U S A. 2004 Jul 13;101(28):10284-9. Epub 2004 Jul 1. PMID:15232006 doi:10.1073/pnas.0402051101
- ↑ Fromme JC, Verdine GL. DNA lesion recognition by the bacterial repair enzyme MutM. J Biol Chem. 2003 Dec 19;278(51):51543-8. Epub 2003 Oct 1. PMID:14525999 doi:10.1074/jbc.M307768200
- ↑ Doublie S, Bandaru V, Bond JP, Wallace SS. The crystal structure of human endonuclease VIII-like 1 (NEIL1) reveals a zincless finger motif required for glycosylase activity. Proc Natl Acad Sci U S A. 2004 Jul 13;101(28):10284-9. Epub 2004 Jul 1. PMID:15232006 doi:10.1073/pnas.0402051101
