Probing Conserved Helical Modules of Portal Complexes by Mass Spectrometry-based Hydrogen/Deuterium Exchange
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- 作者：Sebyung Kang ; Anton Poliakov ; Jennifer Sexton ; Matthew B. Renfrow ; Peter E. Prevelige Jr
- 关键词：hydrogen exchange ; portal protein ; bacteriophage P22 ; mass spectrometry ; virus
- 刊名：Journal of Molecular Biology
- 出版年：2008
- 出版时间：5 September 2008
- 年：2008
- 卷：381
- 期：3
- 页码：772-784
- 全文大小：2363 K
文摘
The Double-stranded DNA bacteriophage P22 has a ring-shaped dodecameric complex composed of the 84 kDa portal protein subunit that forms the central channel of the phage DNA packaging motor. The overall morphology of the P22 portal complex is similar to that of the portal complexes of Phi29, SPP1, T3, T7 phages and herpes simplex virus. Secondary structure prediction of P22 portal protein and its threading onto the crystal structure of the Phi29 portal complexes suggested that the P22 portal protein complex shares conserved helical modules that were found in the dodecameric interfaces of the Phi29 portal complex. To identify the amino acids involved in intersubunit contacts in the P22 portal ring complexes and validate the threading model, we performed comparative hydrogen/deuterium exchange analysis of monomeric and in vitro assembled portal proteins of P22 and the dodecameric Phi29 portal. Hydrogen/deuterium exchange experiments provided evidence of intersubunit interactions in the P22 portal complex similar to those in the Phi29 portal that map to the regions predicted to be conserved helical modules.