Phytochromes and bacterial sensor proteins are related by structural and functional homologies. Hypothesis on phytochrome-mediated signal-transduction.
Phytochrome and bacterial sensor proteins are related by functional and structural homologies. They are both sensors of environmental stimuli and share structural homologies which comprise a domain of about 250 amino acids (about 28 kg.mol-1). This domain is C-terminal in phytochromes and in several bacterial sensor proteins. In both groups of sensors this domain undergoes conformational changes which are caused by the N-terminal part sensing the stimulus. In the case of bacterial sensors, the conformational alteration is, regulated by additional proteins, conferred to a corresponding regulator protein which then acts on transcription. The coincidences between the two groups of sensors are striking enough to assume phytochrome to transduce signals in a way comparable to the bacterial two-component systems.
Schneider-Poetsch
H A
HA
Botanisches Institut II, Universität zu Köln, Germany.
Braun
B
B
Marx
S
S
Schaumburg
A
A
D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics; D015723:Gene Library; D008969:Molecular Sequence Data; D010834:Phytochrome / Q000737:chemistry / Q000235:genetics; D011487:Protein Conformation; D012689:Sequence Homology, Nucleic Acid; D015398:Signal Transduction; D012984:Software
D001426:Bacterial Proteins; D010834:Phytochrome