high mobility group (HMG)-box found in Arabidopsis thaliana high mobility group B protein 9 (HMGB9) and similar proteins
This subfamily contains a group of Arabidopsis thaliana HMGB family proteins, including HMGB9, 10, 11, and 15. They are DNA-binding proteins containing both HMG-box and AT-rich interaction domains. They bind preferentially to DNA with A/T-rich content. HMGB9 is required for karyogamy during female gametophyte development, when the two polar nuclei fuse to form the diploid central cell nucleus. Members of this subfamily have only one HMG-box domain.