Topographical studies of bacteriophage Φ 29 connector bidimensional crystals using scanning tunneling microscopy

✍ Scribed by M. Vélez; G. Rubio; J.M. Valpuesta; J.L. Carrascosa; S. Vieira

• Book ID: 104369150
• Publisher: Elsevier Science
• Year: 1996
• Tongue: English
• Weight: 522 KB
• Volume: 27
• Category: Article
• ISSN: 0968-4328
• DOI: 10.1016/s0968-4328(97)89884-8

✦ Synopsis

Reversed metal replicas of the bacteriophage @ 29 connector bidimensional crystals were observed with the scanning tunneling microscope (STM). This technique can complement structural information obtained from transmission electron microscopy by providing direct height measurements of the structures. The STM images revealed information about the surface topography of the crystals. Individual connectors can be easily distinguished. It is confirmed that neighboring connectors have opposite orientations with respect to the substrate, as has been described previously (Carazo et al., 1986, J. Mol. Biol.. 192, 853 867) and we measure that the smaller domain protrudes 1.3 ± 0.2 nm from the wide domain of the neighboring connectors. An overall view of the crystal surface reveals areas where loose protein has deposited and ordered regions of different thicknesses. These areas can have two different heights with respect to the first layer of the bidimensional crystal: (a) 7.0±0.5 nm, compatible with the the presence of two overlapping layers of proteins and (b) 4.0±0.5 nm, compatible with regions originated by a change in the orientation of neighboring connectors.