Natorff R, Piotrowska M, Paszewski A
Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warsaw.
Mol Gen Genet. 1998 Feb;257(3):255-63. doi: 10.1007/s004380050646.
The Aspergillus nidulans gene sconB, one of the four identified genes controlling sulphur metabolite repression, was cloned and analysed. It encodes a polypeptide of 678 amino acids containing seven WD repeats characteristic of the large WD40 family of eukaryotic regulatory proteins. The SCONB protein has nuclear localisation signals and is very similar to the Neurospora crassa SCON2 and Saccharomyces cerevisiae Met30 proteins, both of which are involved in the regulation of sulphur metabolism. The N. crassa scon-2 gene complements the sconB2 mutation. All three proteins also contain a newly identified motif, the F-box, found in a number of eukaryotic regulatory proteins. This motif is responsible, at least in some cases, for ubiquitin-mediated proteolysis. The sconB transcript is derepressed under sulphur limitation conditions and partly repressed by high methionine.
构巢曲霉基因sconB是已鉴定的控制硫代谢物阻遏的四个基因之一，该基因被克隆并进行了分析。它编码一个由678个氨基酸组成的多肽，含有七个WD重复序列，这是真核生物调节蛋白的大型WD40家族的特征。SCONB蛋白具有核定位信号，并且与粗糙脉孢菌的SCON2和酿酒酵母的Met30蛋白非常相似，这两种蛋白都参与硫代谢的调节。粗糙脉孢菌的scon-2基因可弥补sconB2突变。这三种蛋白还都含有一个新鉴定出的基序，即F-盒，在许多真核生物调节蛋白中都有发现。至少在某些情况下，这个基序负责泛素介导的蛋白水解。sconB转录本在硫限制条件下解除阻遏，并部分受高甲硫氨酸的抑制。
