Crystal structure of Rab6A'(Q72L) mutant reveals unexpected GDP/Mg 2+ binding with opened GTP-binding domain

Young Cheul Shin, Jong Hwan Yoon, Tae Ho Jang, Seo Yun Kim, Won Do Heo, Insuk So, Ju-Hong Jeon, Hyun Ho Park

Research output: Contribution to journalArticleResearchpeer-review

5 Citations (Scopus)

Abstract

The Ras small G protein-superfamily is a family of GTP hydrolases whose activity is regulated by GTP/GDP binding states. Rab6A, a member of the Ras superfamily, is involved in the regulation of vesicle trafficking, which is critical for endocytosis, biosynthesis, secretion, cell differentiation and cell growth. Rab6A exists in two isoforms, termed RabA and Rab6A'. Substitution of Gln72 to Leu72 (Q72L) at Rab6 family blocks GTP hydrolysis activity and this mutation usually causes the Rab6 protein to be constitutively in an active form. Here, we report the crystal structure of the human Rab6A'(Q72L) mutant form at 1.9å resolution. Unexpectedly, we found that Rab6A'(Q72L) possesses GDP/Mg 2+ in the GTP binding pockets, which is formed by a flexible switch I and switch II. Large conformational changes were also detected in the switch I and switch II regions. Our structure revealed that the non-hydrolysable, constitutively active form of Rab6A' can accommodate GDP/Mg 2+ in the open conformation.

Original languageEnglish
Pages (from-to)269-273
Number of pages5
JournalBiochemical and Biophysical Research Communications
Volume424
Issue number2
DOIs
StatePublished - 27 Jul 2012

Fingerprint

Guanosine Triphosphate
Crystal structure
Switches
Monomeric GTP-Binding Proteins
Biosynthesis
Cell growth
Hydrolases
Endocytosis
Conformations
Cell Differentiation
Hydrolysis
Protein Isoforms
Substitution reactions
Mutation
Growth

Keywords

  • Crystal structure
  • Membrane trafficking
  • Rab6A'
  • Small G protein

Cite this

Shin, Young Cheul ; Yoon, Jong Hwan ; Jang, Tae Ho ; Kim, Seo Yun ; Heo, Won Do ; So, Insuk ; Jeon, Ju-Hong ; Park, Hyun Ho. / Crystal structure of Rab6A'(Q72L) mutant reveals unexpected GDP/Mg 2+ binding with opened GTP-binding domain. In: Biochemical and Biophysical Research Communications. 2012 ; Vol. 424, No. 2. pp. 269-273.
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abstract = "The Ras small G protein-superfamily is a family of GTP hydrolases whose activity is regulated by GTP/GDP binding states. Rab6A, a member of the Ras superfamily, is involved in the regulation of vesicle trafficking, which is critical for endocytosis, biosynthesis, secretion, cell differentiation and cell growth. Rab6A exists in two isoforms, termed RabA and Rab6A'. Substitution of Gln72 to Leu72 (Q72L) at Rab6 family blocks GTP hydrolysis activity and this mutation usually causes the Rab6 protein to be constitutively in an active form. Here, we report the crystal structure of the human Rab6A'(Q72L) mutant form at 1.9{\aa} resolution. Unexpectedly, we found that Rab6A'(Q72L) possesses GDP/Mg 2+ in the GTP binding pockets, which is formed by a flexible switch I and switch II. Large conformational changes were also detected in the switch I and switch II regions. Our structure revealed that the non-hydrolysable, constitutively active form of Rab6A' can accommodate GDP/Mg 2+ in the open conformation.",
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Crystal structure of Rab6A'(Q72L) mutant reveals unexpected GDP/Mg 2+ binding with opened GTP-binding domain. / Shin, Young Cheul; Yoon, Jong Hwan; Jang, Tae Ho; Kim, Seo Yun; Heo, Won Do; So, Insuk; Jeon, Ju-Hong; Park, Hyun Ho.

In: Biochemical and Biophysical Research Communications, Vol. 424, No. 2, 27.07.2012, p. 269-273.

Research output: Contribution to journalArticleResearchpeer-review

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AU - Shin, Young Cheul

AU - Yoon, Jong Hwan

AU - Jang, Tae Ho

AU - Kim, Seo Yun

AU - Heo, Won Do

AU - So, Insuk

AU - Jeon, Ju-Hong

AU - Park, Hyun Ho

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