Pirates of the haemoglobin
Authors:Daniel Akinbosede1, Robert Chizea1 and Stephen A. Hare1,†
doi: 10.15698/mic2022.04.775
Volume 9, pp. 84 to 102, published 18/02/2022.
1 School of Life Sciences, University of Sussex, Falmer BN1 9QG, UK.
† Unfortunately, Stephen A. Hare passed away on December 13th 2021: the Editorial Board of Microbial Cell expresses its condolences to his friends and family; resubmission of the revised manuscript occurred before the author’s decease.
Keywords:
nutritional immunity, haemoglobin, pathogenesis, virulence factors, TonB dependent transporters, NEAT proteins, ABC transporters
Corresponding Author(s):
Conflict of interest statement:
The authors declare no competing financial interests.
Please cite this article as:
Daniel Akinbosede, Robert Chizea and Stephen A. Hare (2022). Pirates of the haemoglobin. Microbial Cell 9(4): 84-102. doi: 10.15698/mic2022.04.775
© 2022 Akinbosede et al. This is an open-access article released under the terms of the Creative Commons Attribution (CC BY) license, which allows the unrestricted use, distribution, and reproduc-tion in any medium, provided the original author and source are acknowledged.
Abstract:
Not all treasure is silver and gold; for pathogenic bacteria, iron is the most precious and the most pillaged of metallic elements. Iron is essential for the survival and growth of all life; however free iron is scarce for bacteria inside human hosts. As a mechanism of defence, humans have evolved ways to store iron so as to render it inaccessible for invading pathogens, such as keeping the metal bound to iron-carrying proteins. For bacteria to survive within humans, they must therefore evolve counters to this defence to compete with these proteins for iron binding, or directly steal iron from them. The most populous form of iron in humans is haem: a functionally significant coordination complex that is central to oxygen transport and predominantly bound by haemoglobin. Haemoglobin is therefore the largest source of iron in humans and, as a result, bacterial pathogens in critical need of iron have evolved complex and creative ways to acquire haem from haemoglobin. Bacteria of all cell wall types have the ability to bind haemoglobin at their cell surface, to accept the haem from it and transport this to the cytoplasm for downstream uses. This review describes the systems employed by various pathogenic bacteria to utilise haemoglobin as an iron source within human hosts and discusses their contribution to virulence.