caa a22 4500 445889608 CHVBK 20180317145611.0 cr unu---uuuuu 170323e20110901xx s 000 0 eng 10.1007/s11120-011-9641-5 doi (NATIONALLICENCE)springer-10.1007/s11120-011-9641-5 The CO2-concentrating mechanism of Synechococcus WH5701 is composed of native and horizontally-acquired components [Elektronische Daten] [Benjamin Rae, Britta Förster, Murray Badger, G. Dean Price] The cyanobacterial CO2-concentrating mechanism (CCM) is an effective adaptation that increases the carbon dioxide (CO2) concentration around the primary photosynthetic enzyme Ribulose-1,5-bisphosphate Carboxylase/Oxygenase (RuBisCO). α-Cyanobacteria (those containing Form1-A RuBisCO within cso-type α-carboxysomes) have a limited CCM composed of a small number of Ci-transporters whereas β-cyanobacteria (those species containing Form-1B RuBisCO within ccm-type β-carboxysomes) exhibit a more diverse CCM with a greater variety in Ci-transporter complement and regulation. In the coastal species Synechococcus sp. WH5701 (α-cyanobacteria), the minimal α-cyanobacterial CCM has been supplemented with β-cyanobacterial Ci transporters through the process of horizontal gene transfer (HGT). These transporters are transcriptionally regulated in response to external Ci-depletion however this change in transcript abundance is not correlated with a physiological induction. WH5701 exhibits identical physiological responses grown at 4% CO2 (K 1/2≈31μMCi) and after induction with 0.04% CO2 (K 1/2≈29μMCi). Insensitivity to external Ci concentration is an unusual characteristic of the WH5701 CCM which is a result of evolution by HGT. Our bioinformatic and physiological data support the hypothesis that WH5701 represents a clade of α-cyanobacterial species in transition from the marine/oligotrophic environment to a coastal/freshwater environment. Springer Science+Business Media B.V., 2011 Horizontal gene transfer nationallicence Synechococcus nationallicence WH5701 nationallicence CO2 concentrating mechanism nationallicence Cyanobacteria nationallicence Rae Benjamin Division of Plant Science, Research School of Biology, College of Medicine, Biology and Environment, The Australian National University, Building 46, Biology Place, 0200, Canberra, ACT, Australia aut Förster Britta Division of Plant Science, Research School of Biology, College of Medicine, Biology and Environment, The Australian National University, Building 46, Biology Place, 0200, Canberra, ACT, Australia aut Badger Murray Division of Plant Science, Research School of Biology, College of Medicine, Biology and Environment, The Australian National University, Building 46, Biology Place, 0200, Canberra, ACT, Australia aut Dean Price G. Division of Plant Science, Research School of Biology, College of Medicine, Biology and Environment, The Australian National University, Building 46, Biology Place, 0200, Canberra, ACT, Australia aut Photosynthesis Research Springer Netherlands 109/1-3(2011-09-01), 59-72 0166-8595 109:1-3<59 2011 109 11120 https://doi.org/10.1007/s11120-011-9641-5 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s11120-011-9641-5 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Rae Benjamin Division of Plant Science, Research School of Biology, College of Medicine, Biology and Environment, The Australian National University, Building 46, Biology Place, 0200, Canberra, ACT, Australia aut NATIONALLICENCE 700 1- Förster Britta Division of Plant Science, Research School of Biology, College of Medicine, Biology and Environment, The Australian National University, Building 46, Biology Place, 0200, Canberra, ACT, Australia aut NATIONALLICENCE 700 1- Badger Murray Division of Plant Science, Research School of Biology, College of Medicine, Biology and Environment, The Australian National University, Building 46, Biology Place, 0200, Canberra, ACT, Australia aut NATIONALLICENCE 700 1- Dean Price G. Division of Plant Science, Research School of Biology, College of Medicine, Biology and Environment, The Australian National University, Building 46, Biology Place, 0200, Canberra, ACT, Australia aut NATIONALLICENCE 773 0- Photosynthesis Research Springer Netherlands 109/1-3(2011-09-01), 59-72 0166-8595 109:1-3<59 2011 109 11120 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer