---
title: "Direct Coupling Analysis (DCA)"
type: "entity"
entity_kind: "concept"
status: "hub"
writer_model: "claude-opus-4-8"
canonical_name: "Direct Coupling Analysis"
aliases: ["DCA"]
first_seen: "2026-07-15T00:00:00.000Z"
connects_to: ["protein coevolution","maximum-entropy / Potts models","epistasis","evolved allosteric materials","multiple sequence alignment"]
---


Direct Coupling Analysis is a statistical-inference method that reads a Multiple Sequence Alignment of a protein family and infers which residue pairs are *directly* coupled — disentangling direct from merely correlated (transitively linked) pairs by fitting a global maximum-entropy (Potts / pairwise Boltzmann) model to the alignment's low-order statistics. In protein biology it is the standard tool for predicting contacting/coevolving residues from sequence alone. The vault meets it as a benchmarking target: applied to an evolved allosteric-network ensemble treated as a synthetic alignment, its successes and its limits become measurable against a ground-truth model.

## What this is

A pairwise, low-order inference over sequence statistics. Its power and its ceiling both follow from that: it recovers local couplings well, and it is structurally blind to dependencies that live only at higher order or across long range.

## References

- [[claim-bravi-2020-applies-dca-to-evolved-allosteric-networks-as-synthetic-msa]] — DCA applied to a synthetic MSA of evolved allosteric networks.
- [[claim-dca-predicts-mutation-costs-but-poor-generative-model-of-allostery]] — accurate for point-mutation costs, poor as a generative model.
- [[claim-dca-underestimates-long-range-epistasis-in-allosteric-materials]] — captures short-range, underestimates long-range epistasis; traced to absent long-range correlations.
- [[claim-pdz-dca-couplings-track-short-range-epistasis-more-than-long-range]] — the PDZ-domain real-data validation.
- [[claim-dca-strongest-couplings-only-weakly-influenced-by-phylogenetic-bias]] — phylogenetic sampling bias mainly contaminates intermediate, not the strongest, couplings.