Crystal structure of thermally stable homodimeric cytochrome c'-ß from Thermus thermophilus.
Acta Crystallogr F Struct Biol Commun
; 78(Pt 6): 217-225, 2022 Jun 01.
Article
in En
| MEDLINE
| ID: mdl-35647678
ABSTRACT
Cytochrome c'-ß is a heme protein that belongs to the cytochrome P460 family and consists of homodimeric subunits with a predominantly antiparallel ß-sheet fold. Here, the crystal structure of cytochrome c'-ß from the thermophilic Thermus thermophilus (TTCP-ß) is reported at 1.74â
Å resolution. TTCP-ß has a typical antiparallel ß-sheet fold similar to that of cytochrome c'-ß from the moderately thermophilic Methylococcus capsulatus (MCCP-ß). The phenylalanine cap structure around the distal side of the heme is also similar in TTCP-ß and MCCP-ß, indicating that both proteins similarly bind nitric oxide and carbon monoxide, as observed spectroscopically. Notably, TTCP-ß exhibits a denaturation temperature of 117°C, which is higher than that of MCCP-ß. Mutational analysis reveals that the increased homodimeric interface area of TTCP-ß contributes to its high thermal stability. Furthermore, 14 proline residues, which are mostly located in the TTCP-ß loop regions, possibly contribute to the rigid loop structure compared with MCCP-ß, which has only six proline residues. These findings, together with those from phylogenetic analysis, suggest that the structures of Thermus cytochromes c'-ß, including TTCP-ß, are optimized for function under the high-temperature conditions in which the source organisms live.
Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Thermus thermophilus
/
Cytochromes c'
Language:
En
Journal:
Acta Crystallogr F Struct Biol Commun
Year:
2022
Document type:
Article
Affiliation country: