Crystal structure of arginine methyltransferase 6 from Trypanosoma brucei.
Arginine methylation plays vital roles in the cellular functions of the protozoan Trypanosoma brucei. The T. brucei arginine methyltransferase 6 (TbPRMT6) is a type I arginine methyltransferase homologous to human PRMT6. In this study, we report the crystal structures of apo-TbPRMT6 and its complex with the reaction product S-adenosyl-homocysteine (SAH). The structure of apo-TbPRMT6 displays several features that are different from those of type I PRMTs that were structurally characterized previously, including four stretches of insertion, the absence of strand β15, and a distinct dimerization arm. The comparison of the apo-TbPRMT6 and SAH-TbPRMT6 structures revealed the fine rearrangements in the active site upon SAH binding. The isothermal titration calorimetry results demonstrated that SAH binding greatly increases the affinity of TbPRMT6 to a substrate peptide derived from bovine histone H4. The western blotting and mass spectrometry results revealed that TbPRMT6 methylates bovine histone H4 tail at arginine 3 but cannot methylate several T. brucei histone tails. In summary, our results highlight the structural differences between TbPRMT6 and other type I PRMTs and reveal that the active site rearrangement upon SAH binding is important for the substrate binding of TbPRMT6.
Hefei National Laboratory for Physical Sciences at Microscale and School of Life Sciences, University of Science and Technology of China, Anhui, China.
Chongyuan
C
Wang
Hefei National Laboratory for Physical Sciences at Microscale and School of Life Sciences, University of Science and Technology of China, Anhui, China.
Yuwei
Y
Zhu
Department of Chemistry and Institute of Biomedical Science, Fudan University, Shanghai, China.
Jiajia
J
Chen
Hefei National Laboratory for Physical Sciences at Microscale and School of Life Sciences, University of Science and Technology of China, Anhui, China.
Xu
X
Li
Hefei National Laboratory for Physical Sciences at Microscale and School of Life Sciences, University of Science and Technology of China, Anhui, China.
Junhui
J
Peng
Hefei National Laboratory for Physical Sciences at Microscale and School of Life Sciences, University of Science and Technology of China, Anhui, China.
Jiajing
J
Chen
Hefei National Laboratory for Physical Sciences at Microscale and School of Life Sciences, University of Science and Technology of China, Anhui, China.
Yang
Y
Zou
Hefei National Laboratory for Physical Sciences at Microscale and School of Life Sciences, University of Science and Technology of China, Anhui, China.
Zhiyong
Z
Zhang
Department of Chemistry and Institute of Biomedical Science, Fudan University, Shanghai, China.
Hong
H
Jin
Department of Chemistry and Institute of Biomedical Science, Fudan University, Shanghai, China.
Pengyuan
P
Yang
Hefei National Laboratory for Physical Sciences at Microscale and School of Life Sciences, University of Science and Technology of China, Anhui, China.
Jihui
J
Wu
Hefei National Laboratory for Physical Sciences at Microscale and School of Life Sciences, University of Science and Technology of China, Anhui, China.
Liwen
L
Niu
Hefei National Laboratory for Physical Sciences at Microscale and School of Life Sciences, University of Science and Technology of China, Anhui, China.
Qingguo
Q
Gong
Hefei National Laboratory for Physical Sciences at Microscale and School of Life Sciences, University of Science and Technology of China, Anhui, China.
Maikun
M
Teng
Hefei National Laboratory for Physical Sciences at Microscale and School of Life Sciences, University of Science and Technology of China, Anhui, China.
Yunyu
Y
Shi
D000595:Amino Acid Sequence; D000818:Animals; D001051:Apoenzymes / Q000737:chemistry / Q000378:metabolism; D001120:Arginine / Q000378:metabolism; D015153:Blotting, Western; D020134:Catalytic Domain; D002417:Cattle; D018360:Crystallography, X-Ray; D006657:Histones / Q000378:metabolism; D013058:Mass Spectrometry; D008745:Methylation; D008958:Models, Molecular; D008969:Molecular Sequence Data; D011485:Protein Binding; D055503:Protein Multimerization; D017434:Protein Structure, Tertiary; D011484:Protein-Arginine N-Methyltransferases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D015800:Protozoan Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D012435:S-Adenosylhomocysteine / Q000737:chemistry / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D013379:Substrate Specificity; D014346:Trypanosoma brucei brucei / Q000201:enzymology* / Q000235:genetics / Q000378:metabolism
D001051:Apoenzymes; D006657:Histones; D015800:Protozoan Proteins; D001120:Arginine; D012435:S-Adenosylhomocysteine; D011484:Protein-Arginine N-Methyltransferases