Zn, Cu and Co in cyanobacteria: selective control of metal availability.
Homeostatic systems for essential and non-essential metals create the cellular environments in which the correct metals are acquired by metalloproteins while the incorrect ones are somehow avoided. Cyanobacteria have metal requirements often absent from other bacteria; copper in thylakoidal plastocyanin, zinc in carboxysomal carbonic anhydrase, cobalt in cobalamin but magnesium in chlorophyll, molybdenum in heterocystous nitrogenase, manganese in thylakoidal water-splitting oxygen-evolving complex. This article reviews: an intracellular trafficking pathway for inward copper supply, the sequestration of surplus zinc by metallothionein (also present in other bacteria) and the detection and export of excess cobalt. We consider the influence of homeostatic proteins on selective metal availability.
Cavet
Jennifer S
JS
Biosciences, Medical School, University of Newcastle, Newcastle NE2 4HH, UK.
Borrelly
Gilles P M
GP
Robinson
Nigel J
NJ
D000251:Adenosine Triphosphatases / Q000235:genetics / Q000378:metabolism; D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000096:biosynthesis; D003035:Cobalt / Q000378:metabolism*; D003300:Copper / Q000378:metabolism*; D000458:Cyanobacteria / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D019143:Evolution, Molecular; D008668:Metallothionein / Q000096:biosynthesis; D008670:Metals / Q000633:toxicity; D008969:Molecular Sequence Data; D017434:Protein Structure, Tertiary; D016415:Sequence Alignment; D020524:Thylakoids / Q000502:physiology; D014157:Transcription Factors / Q000737:chemistry; D015032:Zinc / Q000378:metabolism*
D001426:Bacterial Proteins; D008670:Metals; D014157:Transcription Factors; C080048:smtA protein, Synechococcus; C021267:zinc thionein; D003035:Cobalt; D003300:Copper; D008668:Metallothionein; D000251:Adenosine Triphosphatases; D015032:Zinc