Coding

Part:BBa_K4990007

Designed by: Dingjian Zhang   Group: iGEM23_CPU-CHINA   (2023-09-13)
Revision as of 03:08, 19 September 2023 by Norreland (Talk | contribs) (→‎What can it do?)


HlpA

Usage in short

You can use it to target coloretal cancer! Sequence and Features


Assembly Compatibility:
  • 10
    COMPATIBLE WITH RFC[10]
  • 12
    COMPATIBLE WITH RFC[12]
  • 21
    COMPATIBLE WITH RFC[21]
  • 23
    COMPATIBLE WITH RFC[23]
  • 25
    INCOMPATIBLE WITH RFC[25]
    Illegal NgoMIV site found at 231
  • 1000
    COMPATIBLE WITH RFC[1000]

What you need to know!

2006年Tjalsma通过Highly accurate tandem MS方法，找到了一种蛋白Histone-like protein A(HlpA),发现它联系Streptococcus bovis和结直肠癌的桥梁，并推测S.bovis正是通过HlpA与结直肠癌细胞表面的heparan sulfate-proteoglycans(HSPG)结合，介导的S.bovis定植于结直肠癌[1]。

2009年Boleij证明了Streptococcus gallolyticus通过HlpA于结直肠癌细胞表面的HSPG结合[2]。

2016年O'Neil得到了Hlp的晶体结构，指示Hlp为类似蟹钳的结构，钳子部分的碱性氨基酸可以与DNA结合，同时也可以与肝素结合[3]。

2018年Chun Loong Ho利用HlpA与HSPG的结合，构建了一种可以靶向结直肠癌的工程大肠杆菌，拉开了HlpA靶向系统的序幕[4]。

2022年iGEM22_LZU-CHINA 团队，通过合成生物学构建了靶向结直肠癌的大肠杆菌，方法为HlpA靶向肿瘤细胞表面的HSPG[5]。

2023年Tang构建了利用HlpA靶向，Azurin杀伤的工程益生菌，并在结直肠癌小鼠中展现出不错的疗效[6]。


control
Figure A:Crystal structure of HlpA(O'Neil 2016) Figure B:Engineered EcN treat CRC(Chun 2018)
HlpA(Histone-like protein A)正如其名，它能和组蛋白一样结合DNA。它整体形态如同一个蟹钳，能够利用其丝带般的β折叠区与DNA小沟非特异性紧密结合，which leads to significant DNA bending, DNA compaction and negative supercoiling。而S.boivs会通过一种未知的机制将其分泌出胞外，作为anchorless protein，是感染时体液免疫系统的靶标，通过连接细菌lipoteichoic acid(LTA)和结肠上皮细胞上的HSPG介导细菌粘附于结肠肿瘤细胞。

Therefore, HlpA possesses dual capabilities: 1. Targeting colorectal cancer and 2. Non-specifically binding to DNA chains.

What is it?

Here is the structure of HlpA monomer and homodimer.

Two helical segments from each monomeric subunit constitute an α-helical ‘body’ with two protruding β-ribbon ‘arms’ , which extend to bind the DNA helix. These DNA-binding β-ribbons are largely disordered in the absence of DNA

What can it do?

HlpA单体被用于设计融合蛋白，它可以与结直肠癌细胞表面的HSPG进行结合。因此，如果你想用蛋白靶向结直肠癌细胞，你就可以设计一个融合蛋白，将HlpA挂在融合蛋白的一端。如果你想让细胞靶向结直肠癌细胞，则可以为你的底盘细胞量身定制一种包含HlpA的膜蛋白，通过表面展示技术将HlpA表达在地盘细胞表面，它就可以用于靶向结直肠癌细胞[4-6]。

除此之外，HlpA类似于大肠杆菌的HU蛋白。大肠杆菌HU异源二聚体与双链DNA非特异性结合，与结构扭曲的DNA具有更高的亲和力，从而导致显著的DNA弯曲、DNA压实和负超螺旋的形成。HlpA与DNA的结合具有非特异性的，并且对富含AT的DNA具有偏好性。

最后，不得不提到的是，这些HlpA单体可以自组装为同源二聚体，它们之间的结合具有巨大的亲和力。因此，在我们的双靶向肽相关实验中，观察到了显著的二聚化现象。

Referrence

[1]Tjalsma H, Schöller‐Guinard M, Lasonder E, et al. Profiling the humoral immune response in colon cancer patients: diagnostic antigens from Streptococcus bovis[J]. International journal of cancer, 2006, 119(9): 2127-2135.

[2]Boleij A, Schaeps R M J, de Kleijn S, et al. Surface-exposed histone-like protein a modulates adherence of Streptococcus gallolyticus to colon adenocarcinoma cells[J]. Infection and immunity, 2009, 77(12): 5519-5527.

[3]O'Neil P, Lovell S, Mehzabeen N, et al. Crystal structure of histone-like protein from Streptococcus mutans refined to 1.9 Å resolution[J]. Acta Crystallographica Section F: Structural Biology Communications, 2016, 72(4): 257-262.

[4]Ho C L, Tan H Q, Chua K J, et al. Engineered commensal microbes for diet-mediated colorectal-cancer chemoprevention[J]. Nature biomedical engineering, 2018, 2(1): 27-37.

[5]https://2022.igem.wiki/lzu-china/

[6]


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