The evolutionarily conserved trimeric structure of CutA1 proteins suggests a role in signal transduction.
CutA1 are a protein family present in bacteria, plants, and animals, including humans. Escherichia coli CutA1 is involved in copper tolerance, whereas mammalian proteins are implicated in the anchoring of acetylcholinesterase in neuronal cell membranes. The x-ray structures of CutA1 from E. coli and rat were determined. Both proteins are trimeric in the crystals and in solution through an inter-subunit beta-sheet formation. Each subunit consists of a ferredoxin-like (beta1alpha1beta2beta3alpha2beta4) fold with an additional strand (beta5), a C-terminal helix (alpha3), and an unusual extended beta-hairpin involving strands beta2 and beta3. The bacterial CutA1 is able to bind copper(II) in vitro through His2Cys coordination in a type II water-accessible site, whereas the rat protein precipitates in the presence of copper(II). The evolutionarily conserved trimeric assembly of CutA1 is reminiscent of the architecture of PII signal transduction proteins. This similarity suggests an intriguing role of CutA1 proteins in signal transduction through allosteric communications between subunits.
Arnesano
Fabio
F
Magnetic Resonance Center (CERM) and Department of Chemistry, University of Florence, Via Luigi Sacconi 6, 50019, Sesto Fiorentino, Florence, Italy.
Banci
Lucia
L
Benvenuti
Manuela
M
Bertini
Ivano
I
Calderone
Vito
V
Mangani
Stefano
S
Viezzoli
Maria Silvia
MS
D000495:Allosteric Site; D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D002850:Chromatography, Gel; D003001:Cloning, Molecular; D018360:Crystallography, X-Ray; D019281:Dimerization; D029968:Escherichia coli Proteins / Q000737:chemistry* / Q000235:genetics*; D019143:Evolution, Molecular; D005288:Ferredoxins / Q000737:chemistry; D016678:Genome; D008958:Models, Molecular; D008969:Molecular Sequence Data; D008970:Molecular Weight; D011487:Protein Conformation; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D051381:Rats; D017386:Sequence Homology, Amino Acid; D015398:Signal Transduction; D013052:Spectrometry, X-Ray Emission
C094846:CutA protein, E coli; D029968:Escherichia coli Proteins; D005288:Ferredoxins