PDBsum entry 2a2y

DNA,RNA binding protein

PDB id: 2a2y

Contents

Protein chains

89 a.a. *

* Residue conservation analysis

PDB id:

2a2y

Name:

DNA,RNA binding protein

Title:

Nmr structue of sso10b2 from sulfolobus solfataricus

Structure:

DNA/RNA-binding protein alba 2. Chain: a, b. Engineered: yes

Source:

Sulfolobus solfataricus. Organism_taxid: 2287. Gene: alba2. Expressed in: escherichia coli. Expression_system_taxid: 562.

NMR struc:

11 models

Authors:

K.Biyani,M.A.Kahsai,A.T.Clark,T.L.Armstrong,S.P.Edmondson,J.W.Shriver

Key ref:

K.Biyani et al. (2005). Solution structure, stability, and nucleic acid binding of the hyperthermophile protein Sso10b2. Biochemistry, 44, 14217-14230. PubMed id: 16245938 DOI: 10.1021/bi051266r

Date:

23-Jun-05 Release date: 08-Nov-05

Protein chains

Q97ZF4  (ALBA2_SULSO) -  DNA/RNA-binding protein Alba 2 from Saccharolobus solfataricus (strain ATCC 35092 / DSM 1617 / JCM 11322 / P2)

Seq: 89 a.a.

Struc: 89 a.a.

Enzyme reactions

• Enzyme class: E.C.?

DOI no: 10.1021/bi051266r

Biochemistry 44:14217-14230 (2005)

PubMed id: 16245938

Solution structure, stability, and nucleic acid binding of the hyperthermophile protein Sso10b2.

K.Biyani, M.A.Kahsai, A.T.Clark, T.L.Armstrong, S.P.Edmondson, J.W.Shriver.

ABSTRACT

The Sso10b (or Alba) family of proteins is a conserved group of archaeal and eukaryotic proteins which are thought to play a role in both chromatin organization and RNA metabolism. We describe here the solution structure and properties of Sso10b2 from Sulfolobus solfataricus. NMR data including residual dipolar couplings and (15)N relaxation data demonstrated that the protein adopts a beta(1)alpha(1)beta(2)alpha(2)beta(3)beta(4) topology with an IF-3-like fold. The protein dimerizes in solution at 30 degrees C via a hydrophobic surface defined by the C-terminal alpha(2)beta(3)beta(4) elements with a structure similar to one of the putative dimers indicated by previous crystal structures. DSC and circular dichroism data demonstrated an unusual two-state structural transition near the growth temperature which led to an increase in beta-sheet content without dissociation of the dimer. The cooperativity of the transition exceeded that of a dimer at pH 7, demonstrating the presence of higher order oligomers near the growth temperature at pH 7. Reverse titrations of Sso10b2 with nucleic acid showed that the protein binds single-stranded DNA (K(d) of 3 x 10(-)(7) M) with higher affinity than RNA (1.3 x 10(-)(6) M) or double-stranded DNA (1.5 x 10(-)(5) M) in 10 mM KH(2)PO(4) (pH 7.0, 20 degrees C). NMR chemical shift perturbation data indicated that single-stranded DNA and RNA binding occurred across the same dimer interface and encompassed a surface defined by the C-terminal ends of the beta(1), beta(2), and beta(3) strands of each monomer.