ATP binding domain 4 Functions

ATP Binding domain 4 proteins - shows little homology with human protein, and the % sequence ID = 36.8% - under the family of AAHN-like super family

My sequences:

putative n-type ATP pyrophosphatase from Pyrococcus furiosus, the Northeast Structural Genomics Target PfR23

- ATP pyrophosphatase (ATP PPase) is used to assist lysidine formation using a lysine-specific loop and tRNA recognition domain

- Lysidine is a lysine-combined modified cytidine, locating at antcodon wobble position (34) of bacterial tRNA

- Usually ATP-pyrophosphatatse has a domain of GMP synthetase, for adding adenine and help lysine attack on Carbon atom.

http://www.pnas.org/content/102/21/7487.abstract

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- NAD+ synthetase belongs to a member of the family of N-type ATP pyrophosphatase (ATP PPases)

- Some other members of N-type ATP pyrophosphatase include NAD+ synthetase, GMP synthetase, asparagine synthetase and argininosuccinate synthetase

- this family is characterised by strictly conserved fingerprint sequence Ser-Gly-Gly-X-Ser/ Thr-Ser/ Thr at P-loop (this is found by the comparison of 3-D structures of NAD+ synthetase and GMP synthetase

- Since they are in the same family, we can infer their structure similarities and propose the functions of our sequences. - Look for the ATP-binding sites on ref[11]

- Rizzi, M., et al., & Galizzi, A. (1996). Crystal structure of NH3-dependent NAD synthetase from Bacillus subtilis. EMBO J. 15, 5125-5134

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- ([A/S]-[F/y]-S-G-G-[L/V]-D-T-[S/T] is a common consensus sequences that contains a glycine-rich motif that is common to a subset of ATP pyrophosphatases, which is known as 'N-type' ATP pyrophosphatases.

- N-type ATP pyrophosphatases all catalyses a substrate adenylation to activate a carbonyl C=O or carboxyl COO- group for the subsequent attack of a nitrogen nucleopile.

- This glycine-rich motif will form a modified P loop within the nucleotide binding domain, known as 'PP-motif'.

- Lemke, C, T. and Howell, P.L. 2001, The 1.6A Crystal Structure of E.coli Argininosuccinate Synthetase Suggests a Confomational Change during Catalysis, Structure 9:1153-1164.