Proline-rich regions (PRRs) of proteins occur widely in both prokaryotes and eukaryotes.
They are frequently found as multiple tandem repeats, often of considerable length. Despite …

Iron in the form of ferric siderophore complexes and vitamin B12 are transported through the
outer membrane of Gram-negative bacteria by a mechanism which consumes energy. There …

TonB protein couples cytoplasmic membrane electrochemical potential to active transport of
iron-siderophore complexes and vitamin B12 through high-affinity outer membrane …

Escherichia coli possesses two energy‐coupled import systems through which substances
of low concentration and of a size too large to permit diffusion through the porins are …

The utilization by Serratia marcescens of heme bound to hemoglobin requires HasA, an
extracellular heme-binding protein. This unique heme acquisition system was studied in an …

Numerous bacterial proteins are involved in microbial iron uptake and transport and
considerable variation has been found in the uptake schemes used by different bacterial …

Vibrio cholerae was found to have two sets of genes encoding TonB, ExbB and ExbD
proteins. The first set (tonB1, exbB1, exbD1) was obtained by complementation of a V …

The ferric iron‐binding protein (Fbp) expressed by pathogenic Neisseria spp. has been
proposed to play a central role in the high‐affinity acquisition of iron from human transferrin …

TonB protein functions as an energy transducer, coupling cytoplasmic membrane
electrochemical potential to the active transport of vitamin B12 and Fe (III)–siderophore …

Serratia marcescens W225 expresses an unconventional iron (III) transport system. Uptake
of Fe3+ occurs in the absence of an iron (III)-solubilizing siderophore, of an outer membrane …