A hyper thermophile likes it even hotter than the thermophile, up to temperatures that are boiling - and above! This seems like a paradox, since protein will break down at 100+° but many archaea manage by special outer coats that protect them. These S-layers have an amazingly stable structure, that is expensive to produce. It is not that these organisms are 'hanging on' in these conditions - this is their optimum temperature. They grow poorly below 60° a heat that most would find unbearable. Some techniques that they use to stabilise their proteins include:
- N - C terminal bonding to prevent fraying.
- Networks of salt bridges.
- Highly charged surfaces.
- Cysteine-Cysteine covalent connections.