EFFECT OF IRON-DEFICIENCY ON LEVELS OF 2 FERREDOXINS AND FLAVODOXIN IN A CYANOBACTERIUM
EFFECT OF IRON-DEFICIENCY ON LEVELS OF 2 FERREDOXINS AND FLAVODOXIN IN A CYANOBACTERIUM
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DOI：
10.1111/j.1574-6968.1977.tb00612.x
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发表时间：
1977-01-01
影响因子：
2.1
通讯作者：
ROGERS, LJ
中科院分区：
文献类型：
--
作者：
HUTBER, GN;HUTSON, KG;ROGERS, LJ
0. 0.15个单位。这表明黄素氧还蛋白和铁氧还蛋白中的铁离子与铁水平、铁的合成和蛋白质的估计有关，如插入铁a），I型铁氧还蛋白;（u），II型铁氧还蛋白;在蓝细菌I中：很少有矛盾的数据。（：在酶的完全氧化控制中结合黄素的总量（/工作电流！y在净化进展上相对较少，exo tfirms这种观点。图2示出了在由不同铁水平的pre Le改变的培养物中黄素氧还蛋白和铁氧化还原蛋白的中间产物。r~ n. On ';~ 2/aM Fe似乎是一个关键的转录因子，在此浓度下，某些培养物的酶和磷酸铁或铁氧还蛋白都降低，但黄素氧还蛋白的量显著增加。随着1/aM Fe的梳理，两种铁的水平。[I 6}，在大量形成黄氧还蛋白的同时使用显着。这些趋势在饥饿中继续，其中铁浓度已被抑制所有fi '：戏弄到0.5/aM。在这个阶段，可用性是。本实验中，正常情况下（15/aM Fe）存在。显然，没有B的约2：！，这是保持在形成flaylelow thls水平的第一型！从A. nidu！在氮饥饿条件下，通过对四棱藻（Agraenclumquacruplicatum）的一个缺色氨酸突变体和一个缺色氨酸突变体的研究，发现缺色氨酸突变体产生了5种色氨酸生物合成酶，而缺色氨酸突变体没有引起色氨酸生物合成酶活性的变化。Nostoc菌株MAC也含有黄素氧还蛋白合成的B~ n，尽管这在铁离子交换条件1下没有研究，因此黄素氧还蛋白和铁氧还蛋白因此可以B置于列表中。我们承认种族的差异，来自科学院理事会的支持，感谢AJ史密斯博士的帮助。当它们进一步降低毒素时，在其中铁进一步降低至0.5%的培养物中开始限制细胞生长。铁氧还蛋白含量正常，约为2/~ M Fe。在0.5 μ M铁的培养物中，低于铁氧还蛋白的铁氧还蛋白比铁氧还蛋白减少得更快，II型铁氧还蛋白几乎不存在，而I型铁氧还蛋白仍以铁充足的诱饵中的约30%的水平形成。这表明类型！铁氧还蛋白通常在铁中合成。缺乏的条件下，并合成黄氧还蛋白作为替代I1型铁氧还蛋白。PO;尽管已知在某些生物体中具有明显不同的氧化还原电位活性，但由于两种铁氧还蛋白的体内功能不同，因此在生理学方面的意义尚不清楚（KG Hutson等，结果表明，铁氧还蛋白在pI条件下可能参与了机体的病毒感染，并可被黄氧还蛋白所取代。铁氧还蛋白是n表示对照！铁氧还蛋白是铁插入到s '中的铁氧还蛋白，关于铁氧还蛋白的I1 tg数据尚不清楚。卡尔[14]阿尔：《同义词》很少有例外。除氮、硫的存在外，氮、磷的控制也是一个重要的方面。ast [14]。O s仍然
0. cefiu-'0.15 U tions. fbvodoxin luann i~ creased ua ectrum in~ aks af•, u Ior me lype II lel Iron (); M) This indicates thai ion in flavodoxin and ferredoxins with iron level, synthesis of the fe: grown, and protein estimated, as described at insertion of iron a), Type I ferredoxin;(u), Type It ferredoxin; The situation wifi in. in cyanobacteria i: paratively little wq conflicting data.(: ttum of bound flavin in the fully oxidised control of enzym (/ork curtent! y in progress on the purified relatively few exo tfirms this view. intermediary met,'Is of flavodoxin and ferredoxins in cultures altered by the pre Le different iron levels are shown in fig. 2. r~ spectively. On';~ tely 2/aM Fe appears to be a critical con- transcriptional c at which some cultures have decreased tase and phosph~ Le or both ferredoxins, though flavodoxin, resent in significant quantity. With a tease to 1/aM Fe, the levels of both ferre- et al.[I 6}, using markedly while flavodoxin is formed in amounts. These trends are continued in starvation of this which the iron concentration has been repression of all fi': teased to 0.5/aM. At this stage availability sis. The present rt• edoxlns are normally (15/aM Fe) present exists. Clearly No b of about 2:!, and this is maintained at formation tbr flay lelow thls the level of the Type I! ferre- normally expresst ap~ eferential ios~: f phycocyanin from A. nidu! ans under conditions~, f nitrogen starvation, aad Ingrain ttyptophan-requiring auxo~ rophi~ mutant ofAgraencllum quaclruplicatum, found that auxotroph for tryptophan led to d five enzymes of tryptophan biosy ntk, resent results, while not,: oncausive.,:~ ggesl Uaat transcriptional control of fenedoxin synthesis' Nostoc strain MAC also contains the b~ n tbr flavodoxin synthesis althoush this is no~ resscd under iron-sufficien*, conditions ype 1, so that Flavodoxin and the tw3 ferredoxins can therefore b, placed amongst the list) f other cyanobacterial prot~ xin is still whose synthesis L~ contJoUed at the ieve~ of the gen,: fficient culn is preferen-: ement to the ance ef this differ, races We acknowledge.,'upport from the Sc: er~ ce Resea~ oxins have Council, and lhank Dr AJ Smith for vaiu~ bte di.~ u} wn they have further decrease toxins fall significant cultures in which further decreased to 0.5 of iron begins to become limiting for cell growth. The ferredoxins are normall, in the ratio of about 2/~ M Fe. Below doxin decreases more rapidly than the TYl in cultures gsown on 0.5/~ M Fe the Type 11 is virtually absent, whereas the Type I ferredoxin is stll formed at about 30% the level in iron-sufficient lures. This suggests the Type! ferredoxin is tlaUy synthesized in iron. deficient conditions and that flavodoxin is synthesized as a replacement Type I1 ferredoxln. The po; sible significance in physiological terms is not clear as the differ, mc In the In vtvo functions of the two ferredoxins not yet been elucidated, though it is known markedly different redox pot~ ing activities in certain biolc~(KG Hutson et at., unpublisl late that the observations indi ferredoxin may be involved in viral of the organism under pl conditions, and in which it ca replaced by flavodoxin as cml Another observation to en tion of the column p¢ ofiles is absorption at 280 nm when t for the Type I! ferredoxin is n indicates that contro! is ferredoxin aI insertion of iron into the s', with regard to¢ is unclear at little work which I1 tg data. Carr [14] arl: yme symhesis few exception.;, the melabolis', n and, resence of sul, he other ha, ntrol of nit~ phosph~:. ast [14]. O s still