PROSITE documentation PDOC01022

TsaA-like domain signature and profile

The following uncharacterized proteins have been shown [1] to be evolutionary related and to contain a tsaA-like domain:

• Escherichia coli hypothetical protein yaeB and HI0510, the corresponding Haemophilus influenzae protein.
• Agrobacterium tumefaciens Ti plasmid protein virR.
• Pseudomonas aeruginosa protein rcsF.
• Archaeoglobus fulgidus hypothetical protein AF0241.
• Archaeoglobus fulgidus hypothetical protein AF0433.
• Methanococcus jannaschii hypothetical protein MJ1583.
• Methanobacterium thermoautotrophicum hypothetical protein MTH1797.

These are proteins of from 120 to 240 amino-acid residues (with the exception of AF0433 which is 366 residues long). Although found predominantly in prokaryotes the tsaA-like domain is also found in plants, Drosophila and mammals (human, rat, mouse and others):

• Mammalian Nef-associated protein 1 (NAP1).

The structure of the tsaA-like domain contains a six-stranded anti-parallel β-barrel (see <PDB:2NV4>). The tsaA-like domain may bind S-adenosylmethionine (AdoMet) and possesses a methyltransferase activity [2].

As a signature pattern we selected a conserved region in the central part of the domain. We also developed a profile that covers the entire tsaA-like domain.