Maltotriose utilization in lager yeast strains:: MTT1 encodes a maltotriose transporter
Maltotriose utilization in lager yeast strains:: MTT1 encodes a maltotriose transporter
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DOI：
10.1002/yea.1279
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发表时间：
2005-07-30
期刊：
影响因子：
2.6
通讯作者：
Steensma, HY
中科院分区：
文献类型：
--
作者：
Dietvorst, J;Londesborough, J;Steensma, HY
麦芽三糖是麦芽汁中第二丰富的可发酵糖，并且由于不完全发酵，啤酒中残留的麦芽三糖在酿造工业中引起质量和经济问题。为了鉴定可能提高麦芽三糖利用率的基因，我们开发了一个含有来自四个贮藏啤酒菌株和一个实验室酿酒酵母菌株的基因组DNA的文库，并分离了可以在3 mg/l呼吸抑制剂抗霉素A存在下在YP/2%麦芽三糖上生长的转化体。通过这种方法，我们找到了一个与MPH 2和MPH 3有74%相似性，与AGT 1有62%相似性，与MAL 61和MAL 31有91%相似性的基因，它们都编码已知的麦芽糖转运蛋白。此外，该基因与未鉴定的巴斯德酵母mty 1基因（M. Salema-Oom，未公开; NCBI登录号AJ 491328）。因此，我们将该基因命名为MTT 1（mty 1-like transporter）。我们发现该基因存在于四种不同的啤酒菌株中，但在实验室菌株CEN.PK113- 7 D中不存在。从文库中分离的质粒中的ORF缺少从MTT 1的3 ′-末端开始的66个碱基对，但含有54 bp的载体。我们将该ORF命名为MTT 1alt（NCBI登录号DQ 010174）。C-14-麦芽糖和再纯化的C-14-麦芽三糖用于显示MTT 1，特别是MTT 1alt，编码麦芽糖转运蛋白，其对麦芽三糖和麦芽糖的活性之间的比率高于大多数已知的麦芽糖转运蛋白。将MTT 1或MTT 1alt导入啤酒菌株A15中，麦芽三糖的摄取分别提高了约17%和105%。版权所有（c）2005年约翰威利父子有限公司。
Maltotriose is the second most abundant fermentable sugar in wort and, due to incomplete fermentation, residual maltotriose in beer causes both quality and economic problems in the brewing industry. To identify genes that might improve utilization of maltotriose, we developed a library containing genomic DNA from four lager strains and a laboratory Saccharomyces cerevisiae strain and isolated transformants that could grow on YP/2% maltotriose in the presence of 3 mg/l of the respiratory inhibitor antimycin A. In this way we found a gene which shared 74% similarity with MPH2 and MPH3, 62% similarity with AGT1 and 91% similarity with MAL61 and MAL31, all encoding known maltose transporters. Moreover, the gene shared an even higher similarity (98%) with the uncharacterized Saccharomyces pastorianus mty1 gene (M. Salema-Oom, unpublished; NCBI Accession No. AJ491328). Therefore, we named the gene MTT1 (mty1-like transporter). We showed that the gene was present in four different lager strains but was absent from the laboratory strain CEN.PK113-7D. The ORF in the plasmid isolated from the library lacks 66 base pairs from the 3'-end of MTT1 but instead contains 54 bp of the vector. We named this ORF MTT1alt (NCBI Accession No. DQ010174). C-14-Maltose and repurified C-14-maltotriose were used to show that MTT1 and, especially, MTT1alt, encode maltose transporters for which the ratio between activities to maltotriose and maltose is higher than for most known maltose transporters. Introduction of MTT1 or MTT1alt into lager strain A15 raised maltotriose uptake by about 17% or 105%, respectively. Copyright (c) 2005 John Wiley & Sons, Ltd.