The macromolecules that encode and translate information in living systems  exhibit distinctive structural asymmetries, including homochirality or mirror image asymmetry and 3'-5' directionality, that are invariant across all life forms. The evolutionary dynamics that led to these broken symmetries remain unknown. Using a computational model of hypothetical self-replicating autocatalytic heteropolymers, we identify a fundamental symmetry-breaking mechanism that significantly increases the rate of replication of asymmetric heteropolymers, compared to their symmetric counterparts  . This broken-symmetry property, called asymmetric cooperativity, arises when the catalytic influence of inter-strand bonds on their left and right neighbors is unequal. We provide experimental evidence suggestive of its presence in DNA. Asymmetric cooperativity is used to explain, apart from the broken symmetries mentioned above, a number of other properties of DNA that includes four nucleotide alphabet, three nucleotide codons,  helicity, anti-parallel double-strand orientation, heteromolecular base-pairing, asymmetric base compositions, and palindromic instability  .
The macromolecules that encode and translate information in living systems , DNA and RNA, exhibit distinctive structural asymmetries, including homochirality or mirror image asymmetry and 3'-5' directionality, that are invariant across all life forms. The evolutionary advantages of these broken symmetries remain unknown. Here we construct a simple model of hypothetical self-replicating polymers to show that asymmetric autocatalytic polymers are more successful in self-replication compared to their symmetric counterparts in the Darwinian competition for space and common substrates . This broken-symmetry property, called asymmetric cooperativity, arises when the catalytic influence of inter-strand bonds on their left and right neighbors is unequal. Asymmetric cooperativity also leads to simple evolution-based explanations for a number of other properties of DNA that include four nucleotide alphabet, three nucleotide codons, circular genomes, helicity, anti-parallel double-strand orientation, heteromolecular base-pairing, asymmetric base compositions, and palindromic instability , apart from the structural asymmetries mentioned above. Our model results and explanations are consistent with multiple lines of experimental evidence, which include evidence for the presence of asymmetric cooperativity in DNA .
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, DNA and RNA,
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dynamics that led to
advantages of
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Using a computational
Here we construct a simple
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autocatalytic heteropolymers, we identify a fundamental symmetry-breaking mechanism that significantly increases the rate of replication of asymmetric heteropolymers,
polymers to show that asymmetric autocatalytic polymers are more successful in self-replication
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in the Darwinian competition for space and common substrates
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We provide experimental evidence suggestive of its presence in DNA. Asymmetric cooperativity is used to explain, apart from the broken symmetries mentioned above,
Asymmetric cooperativity also leads to simple evolution-based explanations for
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includes
include
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circular genomes,
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, apart from the structural asymmetries mentioned above. Our model results and explanations are consistent with multiple lines of experimental evidence, which include evidence for the presence of asymmetric cooperativity in DNA