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        Science最新发表的论文证明施一公的Science论文的确错了

                            ·方舟子·

    7月16日Science网站发表美国俄勒冈健康与科学大学Eric Gouaux实验室
（同样属“生命科学领域的最高荣誉之一”HHMI）的一篇论文，该论文以较高的
分辨率解析出了ApcT蛋白质晶体结构。这个蛋白质的氨基酸序列和功能与施一公
解析的AdiC相似，通过比较两个蛋白质晶体结构，Gouaux论文的观点与Miller在
Nature发表的论文的结论一样，认为施一公的晶体结构搞错了一圈，导致许多氨
基酸残基，包括一些关键的氨基酸残基，都不在正确的位置上。

Structure and Mechanism of a Na+ Independent Amino Acid Transporter
Paul L. Shaffer, April Goehring, Aruna Shankaranarayanan, and Eric 
Gouaux 
Published online July 16 2009; 10.1126/science.1176088 (Science 
Express Reports) 

"The arginine/agmatine antiporter from Escherichia coli(19) (AdiC) is 
a member of the APC transporter family. Recently Gao et al. reported 
its crystal structure (25). Because ApcT is related to AdiC in amino 
acid sequence and in biochemical function, we compared our structure 
of ApcT, determined at 2.35 A resolution, to the structure of AdiC, 
solved at ~3.6 ? resolution (PDB code 3H5M). As anticipated from the 
relationships in amino acid sequence, the protein folds of ApcT and 
AdiC are similar. We found significant discrepancies, however, between 
the superpositions of the ApcT and AdiC structures and the 
independently aligned amino acid sequences in the transmembrane 
segments 6, 7, and 8 (figs. S11 and S12). Analysis of the structures 
and the sequence alignments leads us to conclude that in the AdiC 
structure, in the regions of TMs 6, 7, and 8 and perhaps to the C 
terminus, the amino acid sequence is off register by several amino 
acid residues relative to ApcT, beginning at the “loop” between TMs 
5 and 6. This means that many residues after the end of TM5, including 
key residues such as Glu208, Tyr239 and Trp293, are “frame shifted” 
by ~4 residues or about one turn of a-helix (25) (figs. S11 to S13). 
Because of this frame-shift, we have not used the AdiC structure in 
our analysis of APC transporters."

(XYS20090720)

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