97-07-066
Abstract:
Sequence Redundancy in Biopolymers:
A Study on RNA and Protein Structures
Peter Schuster and Peter F. Stadler
Mapping sequences onto biopolymer structures
is characterized by redundancy since the numbers of sequences
exceed the numbers of structures. The degree of Redundancy
depends on the notion of structure. Two classes of biopolymers,
RNA molecules and proteins are considered in detail. A general
feature of sequence to structure mappings is the existence of
a few common and many rare structures. Consequences of redundancy
and frequency distribution of RNA structures are shape space
covering and the existence of extended neutral networks.
Populations migrate on neutral networks by a diffusion-like
mechanism. Neutral networks are of fundamental importance for
evolutionary optimization since they enable populations to
escape from local optima of fitness landscapes.
keywords:
Molecular evolution - neutral networks -
protein structures - RNA secondary structures -
sequence-structure map
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