Characterization of the nitrate-nitrite transporter of the major facilitator superfamily (the nrtP gene product) from the cyanobacterium Nostoc punctiforme strain ATCC 29133
Characterization of the nitrate-nitrite transporter of the major facilitator superfamily (the nrtP gene product) from the cyanobacterium Nostoc punctiforme strain ATCC 29133
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DOI：
10.1271/bbb.60286
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发表时间：
2006-11-01
影响因子：
1.6
通讯作者：
Omata, Tatsuo
中科院分区：
文献类型：
--
作者：
Aichi, Makiko;Yoshihara, Saori;Omata, Tatsuo
丝状的，固氮的，淡水蓝藻Nostoc punctiforme菌株ATCC 29133的NpR1527和ApR1526基因的产物分别被鉴定为硝酸盐转运蛋白（NRT）和硝酸盐还原酶（NR），通过互补的蓝藻细长聚球藻菌株PCC 7942的硝酸盐同化突变体。而其他淡水蓝藻，包括S。elongatus的NRT均为ABC型，N. punctiforme属于主要的易化超家族，与海洋蓝细菌（NrtP）中发现的易化超家族同源。与ABC型NRT不同，Nostoc NrtP以高亲和力运输硝酸盐和亚硝酸盐，优先运输硝酸盐。NrtP与ABC型NRT的不同之处还在于其在翻译后水平对铵促进的调节不敏感。N.另一方面，在培养基中添加铵时，抑制了punctiforme，使铵对硝酸盐同化敏感。
The products of the NpR1527 and ApR1526 genes of the filamentous, diazotrophic, fresh-water cyanobacterium Nostoc punctiforme strain ATCC 29133 were identified as a nitrate transporter (NRT) and nitrate reductase (NR) respectively, by complementation of nitrate assimilation mutants of the cyanobacterium Synechococcus elongatus strain PCC 7942. While other fresh-water cyanobacteria, including S. elongatus, have an ATP-binding cassette (ABC)-type NRT, the NRT of N. punctiforme belongs to the major facilitator superfamily, being orthologous to the one found in marine cyanobacteria (NrtP). Unlike the ABC-type NRT, which transports both nitrate and nitrite with high affinity, Nostoc NrtP transported nitrate preferentially over nitrite. NrtP was distinct from ABC-type NRT also in its insensitivity to ammonium-promoted regulation at the post-translational level. The nitrate reductase of N. punctiforme was, on the other hand, inhibited upon addition of ammonium to medium, lending ammonium sensitivity to nitrate assimilation.