隱花色素/光修復(fù)酶家族的光受體調(diào)控所有生命中細(xì)胞對紫外線和藍(lán)光的反應(yīng)：隱花色素傳導(dǎo)對于生長、發(fā)育,、磁敏感性和生物鐘有重要性的信號,；光修復(fù)酶修復(fù)DNA中的光致?lián)p傷。
現(xiàn)在,，Zoltowski等人確定了果蠅的全長度隱花色素的X-射線晶體結(jié)構(gòu),。他們發(fā)現(xiàn)，C-端螺旋體連接在一個已知與光修復(fù)酶中的DNA基質(zhì)相結(jié)合的槽中,，一個在演化中保留下來的色氨酸伸進(jìn)該隱花色素的催化中心中,，模仿能對DNA進(jìn)行修復(fù)的光修復(fù)酶來識別DNA中所受的損傷。（生物谷Bioon.com）
doi:10.1038/nature10618
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Structure of full-length Drosophila cryptochrome
Brian D. Zoltowski, Anand T. Vaidya, Deniz Top, Joanne Widom, Michael W. Young & Brian R. Crane
The cryptochrome/photolyase (CRY/PL) family of photoreceptors mediates adaptive responses to ultraviolet and blue light exposure in all kingdoms of life1, 2, 3, 4, 5. Whereas PLs function predominantly in DNA repair of cyclobutane pyrimidine dimers (CPDs) and 6-4 photolesions caused by ultraviolet radiation, CRYs transduce signals important for growth, development, magnetosensitivity and circadian clocks1, 2, 3, 4, 5. Despite these diverse functions, PLs/CRYs preserve a common structural fold, a dependence on flavin adenine dinucleotide (FAD) and an internal photoactivation mechanism3, 6. However, members of the CRY/PL family differ in the substrates recognized (protein or DNA), photochemical reactions catalysed and involvement of an antenna cofactor. It is largely unknown how the animal CRYs that regulate circadian rhythms act on their substrates. CRYs contain a variable carboxy-terminal tail that appends the conserved PL homology domain (PHD) and is important for function7, 8, 9, 10, 11, 12. Here, we report a 2.3-? resolution crystal structure of Drosophila CRY with an intact C terminus. The C-terminal helix docks in the analogous groove that binds DNA substrates in PLs. Conserved Trp?536 juts into the CRY catalytic centre to mimic PL recognition of DNA photolesions. The FAD anionic semiquinone found in the crystals assumes a conformation to facilitate restructuring of the tail helix. These results help reconcile the diverse functions of the CRY/PL family by demonstrating how conserved protein architecture and photochemistry can be elaborated into a range of light-driven functions.
