中科院北京基因组研究所的胡松年研究员和浙江大学医学院附属二院的胡讯教授合作研究的项目“细菌Phenylobacterium zucineum全基因组测序及分析”取得阶段性成果，相关论文发表在今年第9期的BMC Genomics上。
P.zucineum是合作方从K562细胞系中分离到的兼性细菌。系统分类学上，该细菌属于Phenylobacterium。早期研究者发现Phenylobacterium属细菌可以把苯丙氨酸(phenylalanine)作为唯一碳源，故将该细菌属命名为Phenylobacterium。P.zucineum基因组含有苯丙氨酸代谢通路的所有关键基因，这为Phenylobacterium属细菌利用苯丙氨酸提供了遗传依据。P.zucineum能在细胞外自由生长，又能在体外培养的细胞系中长期生存，具有强大的环境适应能力。P.zucineum基因组编码大量的细胞外周sigma作用因子，转录调节蛋白，双相信号传递蛋白和热激分子伴侣等环境适应相关蛋白。这些蛋白的鉴定很好地解释了P.zucineum所拥有的强大环境适应能力。
另外，作为Phenylobacterium属中唯一具有全基因组序列的细菌，P.zucineum基因组序列将为细菌比较基因组学研究提供有价值的数据基础。 （生物谷Bioon.com）
生物谷推荐原始出处：
BMC Genomics 2008, 9:386doi:10.1186/1471-2164-9-386
Complete genome of Phenylobacterium zucineum – a novel facultative intracellular bacterium isolated from human erythroleukemia cell line K562
Yingfeng Luo 1,2,3 , Xiaoli Xu* 1 , Zonghui Ding* 1 , Zhen Liu1 , Bing Zhang2,3 , Zhiyu Yan1 , Jie Sun1 , Songnian Hu2,3 and Xun Hu1
1 Cancer Institute (Key Laboratory for Cancer Intervention and Prevention, National Ministry of Education, PR China; Key Laboratory of Molecular Biology in Medical Sciences, Zhejiang Province, PR China), the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, PR China
2 James D. Watson Institute of Genome Sciences, Zhejiang University, Hangzhou, PR China
3 Key Laboratory of Genome Sciences and Information, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing, PR China
ackground
Phenylobacterium zucineum is a recently identified facultative intracellular species isolated from the human leukemia cell line K562. Unlike the known intracellular pathogens, P. zucineum maintains a stable association with its host cell without affecting the growth and morphology of the latter.
Results
Here, we report the whole genome sequence of the type strain HLK1T. The genome consists of a circular chromosome (3,996,255 bp) and a circular plasmid (382,976 bp). It encodes 3,861 putative proteins, 42 tRNAs, and a 16S-23S-5S rRNA operon. Comparative genomic analysis revealed that it is phylogenetically closest to Caulobacter crescentus, a model species for cell cycle research. Notably, P. zucineumhas a gene that is strikingly similar, both structurally and functionally, to the cell cycle master regulator CtrA of C. crescentus, and most of the genes directly regulated by CtrA in the latter have orthologs in the former.
Conclusion
This work presents the first complete bacterial genome in the genus Phenylobacterium. Comparative genomic analysis indicated that the CtrA regulon is well conserved between C. crescentus and P. zucineum.
