The npgA/cfwA gene encodes a putative 4′-phosphopantetheinyl transferase which is essential for penicillin biosynthesis in Aspergillus nidulans
The npgA/cfwA gene encodes a putative 4′-phosphopantetheinyl transferase which is essential for penicillin biosynthesis in Aspergillus nidulans
复制标题
DOI：
10.1007/s00294-003-0382-7
复制
发表时间：
2003-06-01
期刊：
影响因子：
2.5
通讯作者：
Turner, G
中科院分区：
文献类型：
--
作者：
Keszenman-Pereyra, D;Lawrence, S;Turner, G
非核糖体肽合成酶，多酮和脂肪酸合成酶具有多酶活性的模块化组织。在所有这些酰基或肽基载体蛋白中，4'-磷酸蚁氨酸（P-pant）作为必需的假基。这是由辅酶a衍生出P-pant基团的4'-磷酸蚁甲酰基转移酶（PPTases）添加的。虽然许多不同特异性的PPTases现在已经从许多细菌中分离出来，但丝状真菌PPTase尚未被表征。通过对烟曲霉抗枯草芽孢杆菌Sfp的基因组序列的数据库检索，我们发现了一个独特的序列，该序列似乎编码PPTase，这是由PPTase中重要的保守残基推断出来的。利用PPTase候选基因在NCBI数据库中进行检索，发现在A. nidulans中有一个意想不到的同源基因为npgA。该基因（cfwA/npgA）的突变先前被确定为导致生长和色素沉着缺陷。为了检测温度敏感的cfwA2突变是否会影响依赖于δ -（l- α -氨基二酰基）- l-半胱氨酸- d -缬氨酸合成酶的青霉素生物合成，我们在允许和非允许温度下建立了calidolactis的生物测定法。cfwA2突变体在非允许温度下不产生青霉素。由于迄今为止尚未在烟烟曲霉基因组中检测到其他PPTase同源物，因此数据表明，单个酶可能能够将辅助因子转移到具有酰基或肽基载体蛋白结构域的广泛酶上。
Non-ribosomal peptide synthetases, polyketides and fatty acid synthetases have a modular organisation of multi-enzymatic activities. In all of them, the acyl or peptidyl carrier proteins have 4'-phosphopantetheine (P-pant) as an essential prosthetic group. This is added by 4'-phosphopantetheinyl transferases (PPTases) that derive the P-pant group from coenzyme A. While many PPTases of varying specificity have now been isolated from a number of bacteria, a filamentous fungal PPTase has yet to be characterised. Through database searching of the Aspergillus fumigatus genome sequence against Sfp from Bacillus subtilis, we identified a unique sequence which appears to encode a PPTase, as deduced from conserved residues considered important in PPTases. The PPTase candidate was used to search the NCBI data base and an unexpected homologue in A. nidulans was identified as npgA. Mutations in this gene (cfwA/npgA) were identified previously as leading to defects in growth and pigmentation. To test whether the temperature-sensitive cfwA2 mutation impairs penicillin biosynthesis, which is dependent on the delta-(L-alpha-aminoadipyl)-L-Cysteinyl-D-valine synthetase, bioassays with B. calidolactis were set up at permissive and non-permissive temperatures. The cfwA2 mutant did not produce penicillin at the non-permissive temperature. Since no other PPTase homologue has been detected in the A. fumigatus genome to date, the data suggest that a single enzyme may be able to transfer the cofactor to a broad range of enzymes with acyl or peptidyl carrier protein domains.