Crystal Structure of the 25 kDa Subunit of Human Cleavage Factor I{m}

Journal Article · Tue Jan 01 04:00:00 EST 2008 · Nucleic Acids Research

DOI:https://doi.org/10.1093/nar/gkn079· OSTI ID:959942

Coseno, M; Martin, G; Berger, C; Gilmartin, G; Keller, W; Doublie, S

Cleavage factor Im is an essential component of the pre-messenger RNA 3'-end processing machinery in higher eukaryotes, participating in both the polyadenylation and cleavage steps. Cleavage factor Im is an oligomer composed of a small 25 kDa subunit (CF Im25) and a variable larger subunit of either 59, 68 or 72 kDa. The small subunit also interacts with RNA, poly(A) polymerase, and the nuclear poly(A)-binding protein. These protein-protein interactions are thought to be facilitated by the Nudix domain of CF Im25, a hydrolase motif with a characteristic {alpha}/{beta}/{alpha} fold and a conserved catalytic sequence or Nudix box. We present here the crystal structures of human CF Im25 in its free and diadenosine tetraphosphate (Ap4A) bound forms at 1.85 and 1.80 Angstroms, respectively. CF Im25 crystallizes as a dimer and presents the classical Nudix fold. Results from crystallographic and biochemical experiments suggest that CF Im25 makes use of its Nudix fold to bind but not hydrolyze ATP and Ap4A. The complex and apo protein structures provide insight into the active oligomeric state of CF Im and suggest a possible role of nucleotide binding in either the polyadenylation and/or cleavage steps of pre-messenger RNA 3'-end processing.

• Research Organization: Brookhaven National Laboratory (BNL) National Synchrotron Light Source
• Sponsoring Organization: Doe - Office Of Science
• DOE Contract Number: AC02-98CH10886
• OSTI ID: 959942
• Report Number(s): BNL--82928-2009-JA
• Journal Information: Nucleic Acids Research, Journal Name: Nucleic Acids Research Journal Issue: 10 Vol. 36; ISSN 0305-1048; ISSN NARHAD
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
CLEAVAGE
CRYSTAL STRUCTURE
DIMERS
HYDROLASES
MACHINERY
NUCLEOTIDES
PROCESSING
PROTEIN STRUCTURE
RNA
national synchrotron light source