Searcharxiv⌕ Search
Home/Archive/arXiv

arXiv · 2208.01491

Mixed Anhydrides at the Intersection Between Peptide and RNA Autocatalytic Sets: Evolution of Biological Coding

Stuart Kauffman·Niles Lehman
View original source ↗Read source document ↗Export metadata ↓

Abstract

We present a scenario for the origin of biological coding. In this context, coding is a semiotic relationship between chemical information stored in one location that links to chemical information stored in a separate location. Coding originated by the cooperative interaction of two, originally separate collectively autocatalytic sets, one for nucleic acids and one for peptides. When these two sets interacted, a series of RNA-folding-directed processes led to their joint cooperativity. The amino acyl adenylate, today amino acid-AMP, was the first covalent association made by these two collectively autocatalytic sets and solidified their interdependence. This molecule is a palimpsest of this era, and is a relic of the original semiotic, and thus coding, relationship between RNA and proteins. More defined coding was driven by selection pressure to eliminate waste in the collective autocatalytic sets. Eventually a 1:1 relationship between single amino acids and short RNA pieces (e.g., three nucleotides) was established, leading to what is today known as the genetic code. Transfer RNA aminoacylating enzymes, or aaRSs, arose concomitantly with the advent of specific coding. The two classes of aaRS enzymes are remnants of the duality of complementary information in two nucleic acid strands, as originally postulated by Rodin and Ohno. Every stage in the evolution of coding was driven by the downward selection on the components of a system to satisfy the Kantian whole. Coding was ultimately forced because there were at least two chemically distinct classes of polymers needed for open-ended evolution; systems with only one polymer cannot exhibit this characteristic. Coding is thus synonymous with life as we know it, and can be thought of as a phase transition in the history of the universe.

Explore related subjects

q-bio.BMphysics.hist-ph

Keep this discovery

BibTeXRIS

Stuart Kauffman, Niles Lehman. 2022-05-25. Mixed Anhydrides at the Intersection Between Peptide and RNA Autocatalytic Sets: Evolution of Biological Coding. https://arxiv.org/abs/2208.01491

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related papers

arXiv2026

Sequence-Informed Geometric Evaluation of RNA 3D Structures

Computational RNA structure pipelines generate many candidate conformations for the same sequence. Reliable evaluation therefore requires more than recognising plausible geometry, it requires determining whether that geometry is compatible with the sequence. We introduce SIRGE, a sequence-informed geometric evaluator that conditions structural representations on nucleotide embeddings from a pretrained RNA language model. Early results show that SIRGE outperforms established evaluators in Kendall--$\tau$ alignment, Top-1 selection, and Top-3 ranking. Controlled comparisons further show that sequence conditioning corrects errors made by an otherwise matched geometric model and improves target-level rank structure. These findings provide initial evidence that pretrained sequence representations supply ranking information that complements geometric reasoning.

q-bio.BM↗
arXiv2026

PocketVE: Stable and Property-Guided Structure-Based Drug Design with Variance-Exploding Diffusion

Protein-conditioned 3D molecule generation is a central challenge in structure-based drug design, requiring a balance between pocket compatibility, molecular properties, and physical geometry. We propose \textbf{PocketVE}, a protein-pocket-conditioned variance-exploding (VE) diffusion framework that couples stable coordinate denoising with inference-time property guidance. Specifically, PocketVE combines an EDM-style training and sampling setup for 3D denoising, classifier-free guidance for multi-property steering without external property classifiers, and adaptive protein perturbation as a training-time pocket regularizer. Evaluated on CrossDocked2020 under the GenBench3D protocol, PocketVE improves Valid$_{3\text{D}}$ from 58.6 to 80.6 and reduces strain energy from 457.4 to 127.9 relative to its TAGMol architectural baseline, while retaining competitive docking and molecular-property scores under moderate guidance. A guidance-scale study shows that moderate guidance gives a favorable balance between target-related objectives and geometric quality, whereas stronger guidance can degrade geometry and distributional fidelity. Pocket-permutation and PoseCheck diagnostics further support pocket-specific spatial compatibility with reduced steric conflicts. Overall, the results suggest that geometric stability and inference-time property guidance should be considered as coupled design objectives.

q-bio.BM↗
arXiv2026

Predicting directional flexibility in proteins

Predicting protein dynamics is a long-standing problem in computational structural biology. Often, protein function critically depends on local directed motions, such as hinge movements, catalytic loop rearrangements and domain reorientations, which can be characterized by directional flexibility and correlated structural motions of the protein backbone. While Molecular Dynamics (MD) simulations provide an established but often prohibitively expensive approach, recent deep generative models aim to reduce this cost by directly predicting conformational ensembles, emulating MD. However, due to their large size and the need to generate several states until the derived dynamical properties converge, these models remain expensive. In this work, we propose BackFlip-2: a fast SE(3)-equivariant graph neural network trained to directly predict dynamical descriptors, such as directional backbone flexibility and pairwise dynamic correlations, from an equilibrium structure. In a series of experiments, we show that our model matches the accuracy of substantially larger ensemble generation models while being orders of magnitude faster, and demonstrate that the proposed equivariant architecture is especially well-suited for capturing anisotropic motions in proteins. BackFlip-2 model weights, training and inference code are available at https://github.com/graeter-group/backflip.

q-bio.BM↗