title: Single-molecule paleoenzymology probes the chemistry of resurrected enzymes.
abstract: It is possible to travel back in time at the molecular level by reconstructing proteins from extinct organisms. Here we report the reconstruction, based on sequence predicted by phylogenetic analysis, of seven Precambrian thioredoxin enzymes (Trx) dating back between ~1.4 and ~4 billion years (Gyr). The reconstructed enzymes are up to 32 °C more stable than modern enzymes, and the oldest show markedly higher activity than extant ones at pH 5. We probed the mechanisms of reduction of these enzymes using single-molecule force spectroscopy. From the force dependency of the rate of reduction of an engineered substrate, we conclude that ancient Trxs use chemical mechanisms of reduction similar to those of modern enzymes. Although Trx enzymes have maintained their reductase chemistry unchanged, they have adapted over 4 Gyr to the changes in temperature and ocean acidity that characterize the evolution of the global environment from ancient to modern Earth.
authors: Department of Biological Sciences, Columbia University, New York, New York, USA. raulpjc@biology.columbia.edu
authors: Raul
authors: R
authors: Perez-Jimenez
authors: Alvaro
authors: A
authors: Inglés-Prieto
authors: Zi-Ming
authors: ZM
authors: Zhao
authors: Inmaculada
authors: I
authors: Sanchez-Romero
authors: Jorge
authors: J
authors: Alegre-Cebollada
authors: Pallav
authors: P
authors: Kosuri
authors: Sergi
authors: S
authors: Garcia-Manyes
authors: T Joseph
authors: TJ
authors: Kappock
authors: Masaru
authors: M
authors: Tanokura
authors: Arne
authors: A
authors: Holmgren
authors: Jose M
authors: JM
authors: Sanchez-Ruiz
authors: Eric A
authors: EA
authors: Gaucher
authors: Julio M
authors: JM
authors: Fernandez
mesh_terms: D001426:Bacterial Proteins / Q000737:chemistry* / Q000235:genetics; D057231:Climate Change; D004795:Enzyme Stability; D019143:Evolution, Molecular; D053476:Extinction, Biological; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D010084:Oxidation-Reduction; D010802:Phylogeny; D017422:Sequence Analysis, DNA; D013879:Thioredoxins / Q000737:chemistry* / Q000235:genetics
chemical_list: D001426:Bacterial Proteins; D013879:Thioredoxins