ABSTRACT
How do proteins diversify their functions across billions of years of evolution? Answering this question is challenging when sequences have diverged beyond recognition, yet protein structure retains evolutionary signal long after sequence similarity has decayed. In this talk, I will show how combining phylogenetic inference, protein structure prediction, and ancestral sequence reconstruction opens new ways to investigate how protein functions originate and
diversify across the tree of life.

I will present two case studies from our recent work on the bacterial flagellar motor. The first traces the evolutionary origin and structural diversity of the MotAB stator complex, the ion channel that powers bacterial swimming, across 27 bacterial phyla. Our analyses reveal that MotAB evolved once from a common ancestral ion transporter before acquiring specialised structural traits to generate torque. The second maps the gain and loss of flagellar motility across more than 11,000 bacterial genomes, identifying the protein components most tightly linked to motility and revealing asymmetric rates of gain and loss across bacterial evolution.

Together, these studies highlight phylogenetics as an increasingly important approach for investigating protein function and structure.

BIOGRAPHY

Caroline Puente-Lelievre is a research fellow at the School of Biological Sciences and Centre for Computational Evolution, University of Auckland, New Zealand. She completed her BSc in Biology at the University of Antioquia, Colombia, and her PhD in Molecular Phylogenetics at James Cook University, Australia. Her research background spans plant systematics, phylogenomics, and bioinformatics. She develops model-based phylogenetic approaches that integrate protein structure data to address fundamental questions about protein diversity at the intersection of evolutionary and structural biology.