|Notes||PaaD-like protein involved in Fe-S cluster assembly (COG2151, DUF59)
1. Paa proteins are components of a multi-component oxygenase (phenylacetate-CoA oxygenase) belonging to the diiron multicomponent oxygenase family. The PaaD component may be equivalent to the gamma subunit of other members of the family. The gamma subunit in absent in some members of the family and its biochemical role is unknown. (Fernández C, Ferrández A, Miñambres B, Díaz E, García JL. Genetic characterization of the phenylacetyl-coenzyme A oxygenase from the aerobic phenylacetic acid degradation pathway of Escherichia coli. Appl Environ Microbiol. 2006 72:7422-6)
2. In Arabidopsis, cyanobacteria, certain other bacteria a PaaD domain is fused to a MRP/NifH-like protein. Arabidopsis gene At3g24430 = HCF101, shown to be involved in 4Fe-4S cluster synthesis in chloroplasts (Lezhneva L, Amann K, Meurer J. The universally conserved HCF101 protein is involved in assembly of [4Fe-4S]-cluster-containing complexes in Arabidopsis thaliana chloroplasts. Plant J. 2004 37:174-85). Homolog of MRP/NifH domain ApbC shown to be involved in Fe-S assembly/repair in Salmonella typhimurium (Skovran E, Downs DM Lack of the ApbC or ApbE protein results in a defect in Fe-S cluster metabolism in Salmonella enterica serovar Typhimurium. J Bacteriol. 2003 185:98-106). Role of PaaD domain not established.
3. 3-D structure available: NMR structure of the conserved hypothetical protein TM0487 from Thermotoga maritima: Implications for 216 homologous DUF59 proteins. M.S. Almeida, T. Herrmann, W. Peti, I.A. Wilson, K. Wüthrich Protein Sci. 2005 14:2880-6.
4. PaaD-like genes cluster strongly with Suf and Isc systems.
5. Iron-sulfur cluster assembly/repair protein ApbC and PaaD-like protein annotation currently very incomplete.