Article Comments - 'The Anabaenasensory rhodopsin transducer defines a novel superfamily of prokaryotic small-molecule binding domains'

Response from the authors

Robson Francisco De Souza — 2009-08-26T09:37:41Z

1) The sequences corressponding to the structures in PDB for the Anabaena protein are indeed different from those derived from the genomic sequence. Given that the domain is short any such change, even if at the termini, appear to distort the key structural elements. This justifies our exclusion of the Anabaena structures from further analysis.

2) This is indeed true and this observation reinforces our basic inference that there is no strict link between functions of solo ASRAH proteins and ASR-type sensory rhodopsins.

A few remarks

Leonid Brown — 2009-08-20T10:24:57Z

1) The authors claim that "Examination of the structures reveals that key structural elements of the
Anabaena representative have been mutated to obtain its crystal structure." I believe this is incorrect. There are parts of the structure which are missing due to disorder, but there are no mutations in the main sequence, with the exception of His-tags added on either of the termini.

2) Not only there are many rhodopsin-less species in which ASRT homologs are found, but there are also several bacterial species having homologs of ASR, but no ASRT.