Pressure Adaptations in Deep-Sea Moritella Dihydrofolate Reductases: Compressibility versus Stability

Biology

卷:10

Ryan W. Penhallurick¹  Toshiko Ichiye¹ 

[1] Department of Chemistry, Georgetown University, Washington, DC 20057, USA;

关键词: deep-sea adaptations;    compressibility;    cavities;    pressure;    potential energy landscape;   

DOI  :  10.3390/biology10111211

来源: DOAJ

【 摘 要 】

Proteins from “pressure-loving” piezophiles appear to adapt by greater compressibility via larger total cavity volume. However, larger cavities in proteins have been associated with lower unfolding pressures. Here, dihydrofolate reductase (DHFR) from a moderate piezophile Moritella profunda (Mp) isolated at ~2.9 km in depth and from a hyperpiezophile Moritella yayanosii (My) isolated at ~11 km in depth were compared using molecular dynamics simulations. Although previous simulations indicate that MpDHFR is more compressible than a mesophile DHFR, here the average properties and a quasiharmonic analysis indicate that MpDHFR and MyDHFR have similar compressibilities. A cavity analysis also indicates that the three unique mutations in MyDHFR are near cavities, although the cavities are generally similar in size in both. However, while a cleft overlaps an internal cavity, thus forming a pathway from the surface to the interior in MpDHFR, the unique residue Tyr103 found in MyDHFR forms a hydrogen bond with Leu78, and the sidechain separates the cleft from the cavity. Thus, while Moritella DHFR may generally be well suited to high-pressure environments because of their greater compressibility, adaptation for greater depths may be to prevent water entry into the interior cavities.

【 授权许可】

Unknown