The domain within your query sequence starts at position 385 and ends at position 578; the E-value for the RB_A domain shown below is 9.58e-119.

TPVASATQSVSRLQSIVAGLKSAPSEQLLNIFESCMRNPMGNIIKIVKGIGETFCQHYTQ
STDKQPGSHIDFAVNRLKLAEILYYKILETIMVQETRRLHGMDMSVLLEQDIFHKSLMAC
CLEIVLFAYSSPRTFPWIIEVLDLQPFYFYKVIEVVIRSEEGLSRDMVKHLNSIEEQILE
SLAWTNNSALWEAL

RB_A

Retinoblastoma-associated protein A domain

• SMART accession number: SM01368
• Description: This domain has the cyclin fold as predicted PMID:8152925, 9495340.
• Interpro abstract (IPR002720):

  Retinoblastoma-like and retinoblastoma-associated proteins may have a function in cell cycle regulation. They form a complex with adenovirus E1A and Simian virus 40 (SV40) large T antigen, and may bind and modulate the function of certain cellular proteins with which T and E1A compete for pocket binding. The proteins may act as tumor suppressors, and are potent inhibitors of E2F-mediated trans-activation. This domain has the cyclin fold [ (PUBMED:8152925) ].

  The crystal structure of the Rb pocket bound to a nine-residue E7 peptide containing the LxCxE motif, shared by other Rb-binding viral and cellular proteins, shows that the LxCxE peptide binds a highly conserved groove on the B-box portion of the pocket; the A-box portion appears to be required for the stable folding of the B box (see IPR002719 ). Also highly conserved is the extensive A-B interface, suggesting that it may be an additional protein-binding site. The A and B boxes each contain the cyclin-fold structural motif, with the LxCxE-binding site on the B-box cyclin fold being similar to a Cdk2-binding site of cyclin A and to a TBP-binding site of TFIIB [ (PUBMED:9495340) ].

  The A and B boxes are found at the C-terminal end of the protein; the A-box is on N-terminal side of the B-box.

• GO process: regulation of cell cycle (GO:0051726)
• GO component: nucleus (GO:0005634)

There are 1890 RB_A domains in 1888 proteins in SMART's nrdb database.

Literature (relevant references for this domain)

Primary literature is listed below; Automatically-derived, secondary literature is also avaliable.

• Lee JO, Russo AA, Pavletich NP
• Structure of the retinoblastoma tumour-suppressor pocket domain bound to apeptide from HPV E7.
• Nature. 1998; 391: 859-65

The pocket domain of the retinoblastoma (Rb) tumour suppressor is central to Rbfunction, and is frequently inactivated by the binding of the human papillomavirus E7 oncoprotein in cervical cancer. The crystal structure of the Rb pocketbound to a nine-residue E7 peptide containing the LxCxE motif, shared by otherRb-binding viral and cellular proteins, shows that the LxCxE peptide binds ahighly conserved groove on the B-box portion of the pocket; the A-box portionappears to be required for the stable folding of the B box. Also highly conservedis the extensive A-B interface, suggesting that it may be an additionalprotein-binding site. The A and B boxes each contain the cyclin-fold structuralmotif, with the LxCxE-binding site on the B-box cyclin fold being similar to aCdk2-binding site of cyclin A and to a TBP-binding site of TFIIB.

Structure (3D structures containing this domain)

3D Structures of RB_A domains in PDB

PDB code	Title
1ad6	DOMAIN A OF HUMAN RETINOBLASTOMA TUMOR SUPPRESSOR
1gh6	RETINOBLASTOMA POCKET COMPLEXED WITH SV40 LARGE T ANTIGEN
1gux	RB POCKET BOUND TO E7 LXCXE MOTIF
1n4m	Structure of Rb tumor suppressor bound to the transactivation domain of E2F-2
1o9k	Crystal structure of the retinoblastoma tumour suppressor protein bound to E2F peptide
2r7g	Structure of the retinoblastoma protein pocket domain in complex with adenovirus E1A CR1 domain
3pom	Crystal Structure of the Unliganded Retinoblastoma Protein Pocket Domain
4elj	Crystal structure of the inactive retinoblastoma protein phosphorylated at T373
4ell	Structure of the inactive retinoblastoma protein pocket domain
4yoo	4YOO
4yos	4YOS
4yoz	4YOZ

Links (links to other resources describing this domain)

• PFAM: RB_A
• INTERPRO: IPR002720