Deduction from Dali and Profunc
From Interpro
Function of isopentenyltransferase = synthesizes isopentenyladensosine 5'-monophosphate
Function of adenylate kinase and guanylate kinase= catalyzes the ATP-dependent phosphorylation of GMP into GDP
Also,
-found a P-loop pattern in adenylate kinase and guanylate kinase
-P-loop is said to be involved in ATP/GTP binding
Since there is a fold similarity between adenylate kinase and 2qgn, P-loop might be present.
Adenylate kinase --> P-loop motif is formed between a β-strand and a α-helix, at its N-terminus.
From PDB and Profunc,
- ligand interacts with AVGKT at position 775-780
- This is towards the end-terminus of the protein sequence and
- This sequence is between a β-strand and a α-helix (PDBsum)
Guanylate kinase has a P-loop as well but different pattern from adenylate kinase.
- Divergence of the P-loop motif
This accounts for the fact that 2qgn cannot be superimposed onto guanylate kinase.
This might be the reason why zinc finger motif is found in humans and not in prokaryotes.
