Characterization of a mesorhizobium loti α-type carbonic anhydrase and its role in symbiotic nitrogen fixation

dc.contributor.author	Kalloniati, C	en
dc.contributor.author	Tsikou, D	en
dc.contributor.author	Lampiri, V	en
dc.contributor.author	Fotelli, MN	en
dc.contributor.author	Rennenberg, H	en
dc.contributor.author	Chatzipavlidis, I	en
dc.contributor.author	Fasseas, C	en
dc.contributor.author	Katinakis, P	en
dc.contributor.author	Flemetakis, E	en
dc.date.accessioned	2014-06-06T06:49:14Z
dc.date.available	2014-06-06T06:49:14Z
dc.date.issued	2009	en
dc.identifier.issn	00219193	en
dc.identifier.uri	http://dx.doi.org/10.1128/JB.01456-08	en
dc.identifier.uri	http://62.217.125.90/xmlui/handle/123456789/4500
dc.subject.other	amide	en
dc.subject.other	bicarbonate	en
dc.subject.other	carbon 13	en
dc.subject.other	carbonate dehydratase	en
dc.subject.other	nitrogen	en
dc.subject.other	nitrogenase	en
dc.subject.other	carbon dioxide	en
dc.subject.other	article	en
dc.subject.other	bacterial growth	en
dc.subject.other	bacterial strain	en
dc.subject.other	bacterium culture	en
dc.subject.other	clone	en
dc.subject.other	culture medium	en
dc.subject.other	cytoplasm	en
dc.subject.other	diffusion	en
dc.subject.other	enzyme activity	en
dc.subject.other	fresh weight	en
dc.subject.other	gene expression	en
dc.subject.other	gene function	en
dc.subject.other	inoculation	en
dc.subject.other	legume	en
dc.subject.other	Lotus	en
dc.subject.other	Mesorhizobium	en
dc.subject.other	mutant	en
dc.subject.other	nitrogen fixation	en
dc.subject.other	nodulation	en
dc.subject.other	nonhuman	en
dc.subject.other	nutrition	en
dc.subject.other	open reading frame	en
dc.subject.other	pH	en
dc.subject.other	priority journal	en
dc.subject.other	protein expression	en
dc.subject.other	proton transport	en
dc.subject.other	recycling	en
dc.subject.other	symbiosis	en
dc.subject.other	Alphaproteobacteria	en
dc.subject.other	amino acid sequence	en
dc.subject.other	biomass	en
dc.subject.other	enzymology	en
dc.subject.other	gene deletion	en
dc.subject.other	gene expression regulation	en
dc.subject.other	genetics	en
dc.subject.other	growth, development and aging	en
dc.subject.other	metabolism	en
dc.subject.other	molecular cloning	en
dc.subject.other	molecular genetics	en
dc.subject.other	physiology	en
dc.subject.other	sequence alignment	en
dc.subject.other	Lotus corniculatus var. japonicus	en
dc.subject.other	Mesorhizobium loti	en
dc.subject.other	Alphaproteobacteria	en
dc.subject.other	Amino Acid Sequence	en
dc.subject.other	Bicarbonates	en
dc.subject.other	Biomass	en
dc.subject.other	Carbon Dioxide	en
dc.subject.other	Carbonic Anhydrases	en
dc.subject.other	Cloning, Molecular	en
dc.subject.other	Gene Deletion	en
dc.subject.other	Gene Expression	en
dc.subject.other	Lotus	en
dc.subject.other	Molecular Sequence Data	en
dc.subject.other	Mutagenesis, Insertional	en
dc.subject.other	Nitrogen Fixation	en
dc.subject.other	Sequence Alignment	en
dc.subject.other	Symbiosis	en
dc.title	Characterization of a mesorhizobium loti α-type carbonic anhydrase and its role in symbiotic nitrogen fixation	en
heal.type	journalArticle	en
heal.identifier.primary	10.1128/JB.01456-08	en
heal.publicationDate	2009	en
heal.abstract	Carbonic anhydrase (CA) (EC 4.2.1.1) is a widespread enzyme catalyzing the reversible hydration of CO2 to bicarbonate, a reaction that participates in many biochemical and physiological processes. Mesorhizobium loti, the microsymbiont of the model legume Lotus japonicus, possesses on the symbiosis island a gene (msi040) encoding an α-type CA homologue, annotated as CAA1. In the present work, the CAA1 open reading frame from M. loti strain R7A was cloned, expressed, and biochemically characterized, and it was proven to be an active a-CA. The biochemical and physiological roles of the CAA1 gene in free-living and symbiotic rhizobia were examined by using an M. loti R7A disruption mutant strain. Our analysis revealed that CAA1 is expressed in both nitrogen-fixing bacteroids and free-living bacteria during growth in batch cultures, where gene expression was induced by increased medium pH. L. japonicus plants inoculated with the CAA1 mutant strain showed no differences in top-plant traits and nutritional status but consistently formed a higher number of nodules exhibiting higher fresh weight, N content, nitrogenase activity, and δ13C abundance. Based on these results, we propose that although CAA1 is not essential for nodule development and symbiotic nitrogen fixation, it may participate in an auxiliary mechanism that buffers the bacteroid periplasm, creating an environment favorable for NH3 protonation, thus facilitating its diffusion and transport to the plant. In addition, changes in the nodule δ13C abundance suggest the recycling of at least part of the HCO3- produced by CAA1. Copyright © 2009, American Society for Microbiology.	en
heal.journalName	Journal of Bacteriology	en
dc.identifier.issue	8	en
dc.identifier.volume	191	en
dc.identifier.doi	10.1128/JB.01456-08	en
dc.identifier.spage	2593	en
dc.identifier.epage	2600	en