Impact of phylogeny on the inference of functional sectors from protein sequence data

Fuente: arXiv
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Auteurs principaux: Dietler, Nicola, Abbara, Alia, Choudhury, Subham, Bitbol, Anne-Florence
Format: Preprint
Publié: 2024
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author Dietler, Nicola
Abbara, Alia
Choudhury, Subham
Bitbol, Anne-Florence
author_facet Dietler, Nicola
Abbara, Alia
Choudhury, Subham
Bitbol, Anne-Florence
contents Statistical analysis of multiple sequence alignments of homologous proteins has revealed groups of coevolving amino acids called sectors. These groups of amino-acid sites feature collective correlations in their amino-acid usage, and they are associated to functional properties. Modeling showed that nonlinear selection on an additive functional trait of a protein is generically expected to give rise to a functional sector. These modeling results motivated a principled method, called ICOD, which is designed to identify functional sectors, as well as mutational effects, from sequence data. However, a challenge for all methods aiming to identify sectors from multiple sequence alignments is that correlations in amino-acid usage can also arise from the mere fact that homologous sequences share common ancestry, i.e. from phylogeny. Here, we generate controlled synthetic data from a minimal model comprising both phylogeny and functional sectors. We use this data to dissect the impact of phylogeny on sector identification and on mutational effect inference by different methods. We find that ICOD is most robust to phylogeny, but that conservation is also quite robust. Next, we consider natural multiple sequence alignments of protein families for which deep mutational scan experimental data is available. We show that in this natural data, conservation and ICOD best identify sites with strong functional roles, in agreement with our results on synthetic data. Importantly, these two methods have different premises, since they respectively focus on conservation and on correlations. Thus, their joint use can reveal complementary information.
format Preprint
id arxiv_https___arxiv_org_abs_2405_04920
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Impact of phylogeny on the inference of functional sectors from protein sequence data
Dietler, Nicola
Abbara, Alia
Choudhury, Subham
Bitbol, Anne-Florence
Populations and Evolution
Biological Physics
Biomolecules
Quantitative Methods
Statistical analysis of multiple sequence alignments of homologous proteins has revealed groups of coevolving amino acids called sectors. These groups of amino-acid sites feature collective correlations in their amino-acid usage, and they are associated to functional properties. Modeling showed that nonlinear selection on an additive functional trait of a protein is generically expected to give rise to a functional sector. These modeling results motivated a principled method, called ICOD, which is designed to identify functional sectors, as well as mutational effects, from sequence data. However, a challenge for all methods aiming to identify sectors from multiple sequence alignments is that correlations in amino-acid usage can also arise from the mere fact that homologous sequences share common ancestry, i.e. from phylogeny. Here, we generate controlled synthetic data from a minimal model comprising both phylogeny and functional sectors. We use this data to dissect the impact of phylogeny on sector identification and on mutational effect inference by different methods. We find that ICOD is most robust to phylogeny, but that conservation is also quite robust. Next, we consider natural multiple sequence alignments of protein families for which deep mutational scan experimental data is available. We show that in this natural data, conservation and ICOD best identify sites with strong functional roles, in agreement with our results on synthetic data. Importantly, these two methods have different premises, since they respectively focus on conservation and on correlations. Thus, their joint use can reveal complementary information.
title Impact of phylogeny on the inference of functional sectors from protein sequence data
topic Populations and Evolution
Biological Physics
Biomolecules
Quantitative Methods
url https://arxiv.org/abs/2405.04920